Topic-Wise Categorized Question Bank<\/title>\r\n <style>\r\n :root {\r\n --primary-color: #0056b3;\r\n --primary-hover: #004494;\r\n --bg-color: #f4f7f6;\r\n --card-bg: #ffffff;\r\n --text-main: #333333;\r\n --text-muted: #666666;\r\n --border-color: #dddddd;\r\n --correct-color: #e6f4ea;\r\n --correct-text: #137333;\r\n --wrong-color: #fce8e6;\r\n --wrong-text: #c5221f;\r\n --deleted-text: #999999;\r\n }\r\n\r\n body {\r\n font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;\r\n background-color: var(--bg-color);\r\n color: var(--text-main);\r\n margin: 0;\r\n padding: 20px;\r\n line-height: 1.6;\r\n }\r\n\r\n .container {\r\n max-width: 800px;\r\n margin: 0 auto;\r\n }\r\n\r\n .header-controls {\r\n background: var(--card-bg);\r\n padding: 15px 20px;\r\n border-radius: 8px;\r\n box-shadow: 0 2px 4px rgba(0,0,0,0.05);\r\n margin-bottom: 20px;\r\n position: sticky;\r\n top: 10px;\r\n z-index: 100;\r\n }\r\n\r\n .mode-toggle, .filter-container {\r\n display: flex;\r\n flex-wrap: wrap;\r\n gap: 10px;\r\n margin-bottom: 10px;\r\n align-items: center;\r\n }\r\n\r\n button {\r\n padding: 8px 16px;\r\n border: 1px solid var(--primary-color);\r\n background: transparent;\r\n color: var(--primary-color);\r\n border-radius: 4px;\r\n cursor: pointer;\r\n font-size: 14px;\r\n transition: all 0.2s ease;\r\n }\r\n\r\n button:hover {\r\n background: #eef5ff;\r\n }\r\n\r\n button.active-btn {\r\n background: var(--primary-color);\r\n color: #fff;\r\n }\r\n\r\n select {\r\n padding: 8px;\r\n border: 1px solid var(--primary-color);\r\n border-radius: 4px;\r\n font-size: 14px;\r\n background: #fff;\r\n color: var(--primary-color);\r\n max-width: 100%;\r\n cursor: pointer;\r\n }\r\n\r\n .status-bar {\r\n display: flex;\r\n justify-content: space-between;\r\n font-size: 14px;\r\n color: var(--text-muted);\r\n border-top: 1px solid var(--border-color);\r\n padding-top: 10px;\r\n margin-top: 10px;\r\n }\r\n\r\n h1 {\r\n font-size: 24px;\r\n text-align: center;\r\n margin-bottom: 20px;\r\n color: var(--primary-color);\r\n }\r\n\r\n .section-heading {\r\n font-size: 18px;\r\n border-bottom: 2px solid var(--primary-color);\r\n padding-bottom: 5px;\r\n margin: 30px 0 15px 0;\r\n color: var(--primary-color);\r\n }\r\n\r\n .card {\r\n background: var(--card-bg);\r\n border-radius: 8px;\r\n padding: 20px;\r\n margin-bottom: 20px;\r\n box-shadow: 0 2px 5px rgba(0,0,0,0.05);\r\n transition: transform 0.2s ease;\r\n border: 1px solid var(--border-color);\r\n }\r\n \r\n .paywall-card {\r\n text-align: center;\r\n padding: 40px 20px;\r\n border: 2px dashed var(--primary-color);\r\n background: #f8fbff;\r\n }\r\n\r\n .paywall-btn {\r\n background: #28a745;\r\n color: #fff;\r\n font-size: 16px;\r\n padding: 12px 24px;\r\n border: none;\r\n border-radius: 30px;\r\n margin-top: 15px;\r\n font-weight: bold;\r\n box-shadow: 0 4px 6px rgba(0,0,0,0.1);\r\n display: inline-block;\r\n text-decoration: none;\r\n }\r\n \r\n .paywall-btn:hover {\r\n background: #218838;\r\n color: #fff;\r\n transform: translateY(-2px);\r\n }\r\n\r\n .q-text {\r\n font-size: 16px;\r\n font-weight: 500;\r\n margin-bottom: 15px;\r\n }\r\n\r\n .options-grid {\r\n display: grid;\r\n grid-template-columns: 1fr 1fr;\r\n gap: 10px;\r\n margin-bottom: 15px;\r\n }\r\n\r\n .option-item {\r\n padding: 10px;\r\n border: 1px solid var(--border-color);\r\n border-radius: 4px;\r\n cursor: pointer;\r\n background: #fafafa;\r\n transition: all 0.2s ease;\r\n }\r\n\r\n .option-item:hover {\r\n background: #f0f0f0;\r\n }\r\n\r\n .option-item.selected {\r\n border-color: var(--primary-color);\r\n background: #eef5ff;\r\n font-weight: bold;\r\n }\r\n\r\n .option-item.correct-opt {\r\n background: var(--correct-color);\r\n border-color: var(--correct-text);\r\n color: var(--correct-text);\r\n }\r\n\r\n .option-item.wrong-opt {\r\n background: var(--wrong-color);\r\n border-color: var(--wrong-text);\r\n color: var(--wrong-text);\r\n }\r\n\r\n .answer-section {\r\n display: none;\r\n margin-top: 15px;\r\n padding-top: 15px;\r\n border-top: 1px dashed var(--border-color);\r\n animation: fadeIn 0.3s ease;\r\n }\r\n\r\n @keyframes fadeIn {\r\n from { opacity: 0; transform: translateY(-5px); }\r\n to { opacity: 1; transform: translateY(0); }\r\n }\r\n\r\n .ans-reveal {\r\n font-weight: bold;\r\n margin-bottom: 10px;\r\n }\r\n\r\n .correct-text { color: var(--correct-text); }\r\n .deleted-text { color: var(--deleted-text); font-style: italic; }\r\n \r\n .disclaimer {\r\n font-size: 12px;\r\n color: #888;\r\n margin-top: 10px;\r\n margin-bottom: 2px;\r\n }\r\n\r\n .memory-trick {\r\n background: #fff8e1;\r\n padding: 10px;\r\n border-left: 4px solid #ffc107;\r\n border-radius: 4px;\r\n font-size: 14px;\r\n }\r\n\r\n .explanation {\r\n background: #e3f2fd;\r\n padding: 10px;\r\n border-left: 4px solid #2196f3;\r\n border-radius: 4px;\r\n font-size: 14px;\r\n margin-top: 10px;\r\n }\r\n\r\n .interaction-bar {\r\n margin-top: 15px;\r\n display: flex;\r\n flex-wrap: wrap;\r\n align-items: center;\r\n gap: 15px;\r\n font-size: 13px;\r\n }\r\n\r\n .vote-btn {\r\n padding: 4px 8px;\r\n font-size: 12px;\r\n border: 1px solid #ccc;\r\n color: #555;\r\n }\r\n\r\n .report-btn {\r\n color: var(--wrong-text);\r\n border-color: var(--wrong-text);\r\n margin-left: auto;\r\n }\r\n \r\n .report-btn:hover {\r\n background: var(--wrong-color);\r\n }\r\n\r\n #submit-fab {\r\n position: fixed;\r\n bottom: 30px;\r\n right: 30px;\r\n background: #28a745;\r\n color: white;\r\n border: none;\r\n padding: 15px 25px;\r\n font-size: 16px;\r\n font-weight: bold;\r\n border-radius: 30px;\r\n box-shadow: 0 4px 10px rgba(0,0,0,0.2);\r\n cursor: pointer;\r\n z-index: 1000;\r\n display: none;\r\n transition: transform 0.2s;\r\n }\r\n\r\n #submit-fab:hover {\r\n transform: scale(1.05);\r\n background: #218838;\r\n }\r\n\r\n .results-panel {\r\n background: var(--card-bg);\r\n padding: 20px;\r\n border-radius: 8px;\r\n margin-bottom: 20px;\r\n text-align: center;\r\n box-shadow: 0 2px 5px rgba(0,0,0,0.1);\r\n display: none;\r\n border: 2px solid var(--primary-color);\r\n }\r\n\r\n @media (max-width: 600px) {\r\n .options-grid { grid-template-columns: 1fr; }\r\n .interaction-bar { flex-direction: column; align-items: flex-start; }\r\n .report-btn { margin-left: 0; }\r\n }\r\n <\/style>\r\n<\/head>\r\n<body>\r\n\r\n<div class=\"container\">\r\n <h1>\ud83d\udcdd Topic-Wise Question Bank<\/h1>\r\n\r\n <div class=\"header-controls\">\r\n <div class=\"mode-toggle\">\r\n <strong>Mode:<\/strong>\r\n <button id=\"btn-mode-learning\" class=\"active-btn\" onclick=\"setMode('learning')\">\ud83d\udcd6 Learning Mode<\/button>\r\n <button id=\"btn-mode-attempt\" onclick=\"setMode('attempt')\">\u23f1\ufe0f Attempt Mode<\/button>\r\n <button id=\"btn-toggle-all\" onclick=\"toggleAllAnswers()\" style=\"margin-left: auto;\">Reveal All Answers<\/button>\r\n <\/div>\r\n \r\n <div class=\"filter-container\" id=\"filter-buttons\">\r\n <\/div>\r\n\r\n <div class=\"status-bar\">\r\n <span id=\"question-counter\">Showing 0 questions<\/span>\r\n <span id=\"score-display\" style=\"display:none; font-weight: bold; color: var(--primary-color);\"><\/span>\r\n <\/div>\r\n <\/div>\r\n\r\n <div id=\"results-panel\" class=\"results-panel\">\r\n <h2 id=\"final-score-text\">Score: 0 \/ 0<\/h2>\r\n <p>Review your answers below.<\/p>\r\n <button id=\"btn-reattempt\" onclick=\"reattemptWrong()\" style=\"background: var(--primary-color); color: white;\">\ud83d\udd04 Reattempt Wrong Questions<\/button>\r\n <\/div>\r\n\r\n <div id=\"quiz-container\"><\/div>\r\n <button id=\"submit-fab\" onclick=\"submitTest()\">Submit Test<\/button>\r\n<\/div>\r\n\r\n<script>\r\n var questionsData = [\r\n { id: 1, topic: \"PN Junction Diode\", question: \"Which among the following semiconductor materials exhibits the highest breakdown voltage in a PN junction diode for similar doping levels?\", options: [\"GaAs\", \"Ge\", \"Si\", \"GaN\"], answer: 3, deleted: false, memoryTrick: \"GaN = Giant Amount of eNergy.\", explanation: \"GaN (Gallium Nitride) is a wide-bandgap material, leading to much higher breakdown voltages.\" },\r\n { id: 2, topic: \"PN Junction Diode\", question: \"The dynamic resistance of a forward-biased PN diode increases with\", options: [\"Increasing the forward bias voltage\", \"Decreasing the DC bias current\", \"Increasing the doping concentration\", \"Reducing the temperature\"], answer: 1, deleted: false, memoryTrick: \"Dynamic resistance is inversely proportional to current (r = VT\/I).\", explanation: \"As DC bias current decreases, dynamic resistance increases.\" },\r\n { id: 3, topic: \"PN Junction Diode\", question: \"Zener and Avalanche breakdown phenomena display opposite temperature coefficients because\", options: [\"Zener breakdown has a negative temperature coefficient, while Avalanche breakdown has a positive temperature coefficient\", \"Zener breakdown has a positive temperature coefficient, while Avalanche breakdown has a negative temperature coefficient\", \"Both have positive temperature coefficients\", \"Both have negative temperature coefficients\"], answer: 0, deleted: false, memoryTrick: \"Zener = Zero or sub-zero (negative). Avalanche = Adds up (positive).\", explanation: \"Zener breakdown voltage decreases with temperature (negative), while Avalanche increases (positive).\" },\r\n { id: 4, topic: \"PN Junction Diode\", question: \"For semiconductor diodes, the barrier potential decreases by approximately\", options: [\"2 mV for each \u00b0C rise in temperature\", \"2 mV for each \u00b0C drop in temperature\", \"0.7 mV for each \u00b0C rise in temperature\", \"2 V for each \u00b0C rise in temperature\"], answer: 0, deleted: false, memoryTrick: \"Hotter diode = barrier drops by 2mV\/\u00b0C.\", explanation: \"As temperature rises, intrinsic carrier concentration increases, reducing the barrier potential by roughly 2-2.5 mV\/\u00b0C.\" },\r\n { id: 5, topic: \"Rectifiers and Voltage Multipliers\", question: \"The average value of a half wave rectifier is\", options: [\"2 Vm\/\u03c0\", \"Vm\/\u03c0\", \"Vm\/2\", \"Vm\/\u221a2\"], answer: 1, deleted: false, memoryTrick: \"Half wave = one \u03c0. Full wave = two \u03c0s.\", explanation: \"Integrating a sine wave over a half cycle gives Vm\/\u03c0.\" },\r\n { id: 9, topic: \"Rectifiers and Voltage Multipliers\", question: \"Poor voltage regulation in voltage doublers can be improved with\", options: [\"Increasing input frequency\", \"Using smaller capacitors\", \"Reducing diode forward voltage\", \"Using large value capacitors\"], answer: 3, deleted: false, memoryTrick: \"Bigger caps = Better regulation.\", explanation: \"Larger capacitors store more charge, reducing ripple and improving voltage regulation.\" },\r\n { id: 6, topic: \"Optoelectronic Devices\", question: \"The switching time of an opto coupler decreases with\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 7, topic: \"Optoelectronic Devices\", question: \"Which parameter in a solar cell ensures the maximum number of photons of light energy reach the p-n junction?\", options: [\"High series resistance\", \"Anti Reflective Coating (ARC) and surface texturing\", \"Thick glass cover\", \"High doping concentration\"], answer: 1, deleted: false, memoryTrick: \"ARC traps the light.\", explanation: \"Anti-reflective coating minimizes light bouncing off the surface, maximizing absorption.\" },\r\n { id: 8, topic: \"Optoelectronic Devices\", question: \"Which material is most commonly used in Light Dependent Resistors (LDRs) due to its high photosensitivity in the visible spectrum?\", options: [\"Cadmium Sulphide (CdS)\", \"Silicon (Si)\", \"Germanium (Ge)\", \"Gallium Arsenide (GaAs)\"], answer: 0, deleted: false, memoryTrick: \"CdS = Catches Daylight Swiftly.\", explanation: \"CdS has a spectral response similar to the human eye, making it ideal for visible light LDRs.\" },\r\n { id: 10, topic: \"Optoelectronic Devices\", question: \"The output current in a phototransistor depends on\", options: [\"Temperature\", \"Reverse saturation current\", \"Light intensity\", \"Collector-emitter voltage\"], answer: 2, deleted: false, memoryTrick: \"Photo = Light. Current depends on light.\", explanation: \"The base current is generated by photons, so output collector current is directly proportional to light intensity.\" },\r\n { id: 11, topic: \"Bipolar Junction Transistor (BJT)\", question: \"In a transistor amplifier circuit negative feedback __________ amplifier bandwidth.\", options: [\"Decreases\", \"Increases\", \"Narrow\", \"No change\"], answer: 1, deleted: false, memoryTrick: \"Feedback trades gain for bandwidth (bandwidth increases).\", explanation: \"Negative feedback flattens frequency response, extending upper and lower cut-off frequencies.\" },\r\n { id: 12, topic: \"Bipolar Junction Transistor (BJT)\", question: \"Fixed biasing circuit RB = 330 K ohm, RC = 15.5 K ohm, VCC = 12 V and IC = 3 mA. Determine VCE.\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 13, topic: \"Bipolar Junction Transistor (BJT)\", question: \"In transistor configuration how \u03b2 of a transistor is related to its \u03b1?\", options: [\"\u03b2 = \u03b1 \/ \u03b1 + 1\", \"\u03b2 = \u03b1 \/ 1 \u2013 \u03b1\", \"\u03b1 = \u03b2 \/ 1 \u2013 \u03b2\", \"\u03b1 = \u03b2 \/ \u03b2 \u2013 1\"], answer: 1, deleted: false, memoryTrick: \"\u03b2 is bigger than \u03b1, so divide \u03b1 by a number less than 1 (1 - \u03b1).\", explanation: \"Beta is the common-emitter current gain, Alpha is common-base. \u03b2 = \u03b1\/(1-\u03b1).\" },\r\n { id: 14, topic: \"Bipolar Junction Transistor (BJT)\", question: \"An RC coupled amplifier has a voltage gain of 100 in the frequency range of 500 \u2013 20 KHz. Calculate gain in dB.\", options: [\"10\", \"100\", \"40\", \"80\"], answer: 2, deleted: false, memoryTrick: \"dB = 20 * log10(Voltage Gain). 20 * log10(100) = 20 * 2 = 40.\", explanation: \"Voltage gain in dB is 20 * log(100) = 40 dB.\" },\r\n { id: 15, topic: \"Field Effect Transistor (FET)\", question: \"Field Effect Transistor (FET) is a ________ device.\", options: [\"Voltage Control\", \"Current Control\", \"Voltage and Current Control\", \"None of the above\"], answer: 0, deleted: false, memoryTrick: \"Field = Voltage.\", explanation: \"The gate-source voltage controls the drain current, drawing practically zero gate current.\" },\r\n { id: 17, topic: \"Field Effect Transistor (FET)\", question: \"Change in Gate to Source voltage of FET is 1 Volt and Change in drain current is 1.5 mA. Determine the magnitude of transconductance.\", options: [\"1.5 mS\", \"0.5 mS\", \"2 mS\", \"2.5 mS\"], answer: 0, deleted: false, memoryTrick: \"gm = \u0394Id \/ \u0394Vgs. 1.5 \/ 1 = 1.5.\", explanation: \"Transconductance is the ratio of change in drain current to change in gate-source voltage.\" },\r\n { id: 18, topic: \"Field Effect Transistor (FET)\", question: \"MOSFET's have an important property that they can be used as\", options: [\"A Resistor\", \"A Capacitor\", \"An Amplifier\", \"All of the above\"], answer: 3, deleted: false, memoryTrick: \"MOSFETs do it all.\", explanation: \"MOSFETs can act as voltage-controlled resistors (linear region), capacitors (gate oxide), and amplifiers (saturation region).\" },\r\n { id: 19, topic: \"Unijunction Transistor (UJT)\", question: \"When emitter terminal of a Unijunction Transistor (UJT) is open the resistance of the base terminal is\", options: [\"Very low\", \"Very high\", \"Low\", \"Moderate\"], answer: 1, deleted: false, memoryTrick: \"Open emitter = basically just a chunk of lightly doped silicon = High resistance.\", explanation: \"Without emitter current, the interbase resistance (RBB) is typically high (5k - 10k ohms).\" },\r\n { id: 20, topic: \"Unijunction Transistor (UJT)\", question: \"VI Characteristics of a Unijunction Transistor (UJT), the region between the peak point and valley point is called\", options: [\"Saturation Region\", \"Cut-off Region\", \"Negative Resistance Region\", \"Peak Point Voltage\"], answer: 2, deleted: false, memoryTrick: \"Voltage drops while current rises = Negative Resistance.\", explanation: \"In this region, increasing current results in decreasing voltage, characteristic of negative resistance devices.\" },\r\n { id: 16, topic: \"Oscillators\", question: \"Which of the following oscillator provides high accuracy of oscillation?\", options: [\"Wein Bridge Oscillator\", \"Colpits Oscillator\", \"Hartley Oscillator\", \"Crystal Oscillator\"], answer: 3, deleted: false, memoryTrick: \"Crystals are precise (think quartz watches).\", explanation: \"Crystal oscillators use the piezoelectric effect of a quartz crystal, providing extremely stable and accurate frequencies.\" },\r\n { id: 21, topic: \"Operational Amplifiers\", question: \"Slew rate limits the op-amp's performance at\", options: [\"DC\", \"Low frequency\", \"High frequency\", \"Zero\"], answer: 2, deleted: false, memoryTrick: \"Slew = Speed. High speed = High frequency.\", explanation: \"Slew rate is the maximum rate of change of output voltage, which restricts high-frequency performance.\" },\r\n { id: 22, topic: \"Operational Amplifiers\", question: \"A Schmidt trigger circuit using an op-amp is mainly used for\", options: [\"Amplifying analog signals\", \"Converting analog signals to digital pulses\", \"Frequency multiplication\", \"Phase shifting\"], answer: 1, deleted: false, memoryTrick: \"Trigger = Snap to Digital.\", explanation: \"It uses positive feedback to snap between two states, turning noisy analog signals into clean digital square waves.\" },\r\n { id: 24, topic: \"Operational Amplifiers\", question: \"In an op-amp differentiator circuit, the input element is\", options: [\"Diode\", \"Transistor\", \"Capacitor\", \"Inductor\"], answer: 2, deleted: false, memoryTrick: \"Differentiator = Capacitor first (DC). Integrator = Resistor first.\", explanation: \"The capacitor is in series with the input, producing an output proportional to the derivative of the input voltage.\" },\r\n { id: 23, topic: \"555 Timer\", question: \"In the functional block diagram of 555 timer, the discharge transistor is\", options: [\"PNP transistor connected to Vcc\", \"NPN transistor connected to ground\", \"FET connected to threshold pin\", \"PNP connected to control pin\"], answer: 1, deleted: false, memoryTrick: \"Discharge = Dump to ground via NPN.\", explanation: \"Pin 7 connects to the open collector of an NPN transistor, which discharges the external timing capacitor to ground.\" },\r\n { id: 25, topic: \"Voltage Regulators\", question: \"LM317 has how many pins?\", options: [\"2\", \"3\", \"4\", \"8\"], answer: 1, deleted: false, memoryTrick: \"LM317 = 3 pins (Adj, Vout, Vin).\", explanation: \"It's a standard 3-terminal adjustable voltage regulator.\" },\r\n { id: 26, topic: \"DAC and ADC\", question: \"The reference voltage (Vref) in a DAC is used to\", options: [\"Set the output voltage range\", \"Stabilize the input\", \"Reduce power\", \"Control clock frequency\"], answer: 0, deleted: false, memoryTrick: \"Reference = Scale size.\", explanation: \"Vref determines the maximum analog output voltage when all digital bits are 1.\" },\r\n { id: 27, topic: \"DAC and ADC\", question: \"The output impedance of an ideal R\u20132R ladder DAC is\", options: [\"R\", \"2R\", \"R\/2\", \"Infinite\"], answer: 0, deleted: false, memoryTrick: \"Look back into the ladder, it always equals R.\", explanation: \"By Thevenin's theorem, looking into any node of an infinite R-2R ladder yields an equivalent resistance of R.\" },\r\n { id: 28, topic: \"DAC and ADC\", question: \"The accuracy of ramp-type ADC mainly depends on\", options: [\"Clock frequency and ramp linearity\", \"Comparator gain\", \"Input resistance\", \"Counter type\"], answer: 0, deleted: false, memoryTrick: \"Ramp depends on time (clock) and slope (linearity).\", explanation: \"A steady clock and a perfectly linear ramp voltage are required for accurate time-to-voltage conversion.\" },\r\n { id: 29, topic: \"DAC and ADC\", question: \"A higher number of bits in an ADC gives\", options: [\"Lower resolution\", \"Higher resolution\", \"Slower conversion\", \"Lower accuracy\"], answer: 1, deleted: false, memoryTrick: \"More bits = more details = higher resolution.\", explanation: \"Resolution is 2^n. More bits mean smaller step sizes and greater precision.\" },\r\n { id: 30, topic: \"DAC and ADC\", question: \"The conversion time of a successive approximation ADC depends on\", options: [\"Input voltage magnitude\", \"Step size\", \"Number of bits and clock frequency\", \"None of these\"], answer: 2, deleted: false, memoryTrick: \"SAR takes exactly 'N' clock cycles for 'N' bits.\", explanation: \"It requires one clock cycle per bit of resolution, regardless of the input voltage.\" },\r\n { id: 31, topic: \"Two-Port Networks\", question: \"Which impedance is defined as the impedance seen looking into the network with the other end terminated by the same impedance?\", options: [\"Iterative impedance\", \"Characteristic impedance\", \"Input impedance\", \"Output impedance\"], answer: 0, deleted: false, memoryTrick: \"Iterative = Repeating the same impedance.\", explanation: \"Iterative impedance is the impedance that, when connected to one port, presents the same impedance at the other port.\" },\r\n { id: 32, topic: \"Two-Port Networks\", question: \"For symmetrical T networks, the characteristic impedance is\", options: [\"Arithmetic mean of open and short circuit impedances\", \"Geometric mean of open and short circuit impedances\", \"Sum of all impedances\", \"Difference of all impedances\"], answer: 1, deleted: false, memoryTrick: \"Z0 = \u221a(Zoc * Zsc). Root = Geometric mean.\", explanation: \"Characteristic impedance is the square root of the product of open-circuit and short-circuit impedances.\" },\r\n { id: 33, topic: \"Transmission Lines\", question: \"Which of the following affects the characteristic impedance Z0 of a lossless transmission line?\", options: [\"Only resistance R\", \"Only inductance L and capacitance C\", \"Conductance G only\", \"Frequency only\"], answer: 1, deleted: false, memoryTrick: \"Lossless means R=0, G=0. So only L and C remain.\", explanation: \"For a lossless line, Z0 = \u221a(L\/C).\" },\r\n { id: 38, topic: \"Transmission Lines\", question: \"Standing waves occur on a transmission line due to\", options: [\"Perfectly matched load\", \"Reflections caused by load mismatch\", \"High voltage at the source\", \"Infinite line length\"], answer: 1, deleted: false, memoryTrick: \"Waves stand when they crash back (reflect).\", explanation: \"When load impedance doesn't match line impedance, energy reflects back, interfering with the forward wave to create standing waves.\" },\r\n { id: 39, topic: \"Transmission Lines\", question: \"If SWR is greater than 1, it indicates\", options: [\"No reflected wave\", \"Presence of reflected wave leading to standing waves\", \"Power supply failure\", \"Perfect transmission line operation\"], answer: 1, deleted: false, memoryTrick: \"SWR = 1 is perfect. >1 means reflection.\", explanation: \"Standing Wave Ratio (SWR) > 1 means the reflection coefficient is non-zero, indicating a mismatch.\" },\r\n { id: 34, topic: \"Attenuators and Equalizers\", question: \"A constant resistance equalizer typically results in\", options: [\"Variable input impedance\", \"Constant input impedance over frequency range\", \"Variable power loss\", \"No frequency shaping\"], answer: 1, deleted: false, memoryTrick: \"Name says it all: Constant Resistance.\", explanation: \"It provides a constant resistive input impedance at all frequencies, preventing reflections.\" },\r\n { id: 35, topic: \"Attenuators and Equalizers\", question: \"Which parameter is critical for designing attenuator resistor values in T and Pi networks?\", options: [\"Voltage swing\", \"Frequency of operation\", \"Characteristic impedance and attenuation level\", \"Temperature coefficient\"], answer: 2, deleted: false, memoryTrick: \"You need to know how much to attenuate (dB) and the line impedance (Z0).\", explanation: \"Design formulas require the desired attenuation in dB (or N) and the system's characteristic impedance (Ro).\" },\r\n { id: 36, topic: \"Attenuators and Equalizers\", question: \"What is the benefit of a Pi-pad attenuator over a T-pad attenuator?\", options: [\"Uses fewer components\", \"Better impedance matching at high frequencies\", \"Simpler design\", \"Higher power amplification\"], answer: 1, deleted: false, memoryTrick: \"Pi handles high freq capacitance better.\", explanation: \"At RF frequencies, shunt capacitances are easier to absorb into the parallel arms of a Pi network.\" },\r\n { id: 37, topic: \"Filters\", question: \"A filter designed to eliminate frequencies in a specific range while allowing others to pass is called\", options: [\"Band-pass filter\", \"Band-stop filter\", \"Low-pass filter\", \"High-pass filter\"], answer: 1, deleted: false, memoryTrick: \"Stops a specific band.\", explanation: \"A band-stop (or notch) filter rejects frequencies between two specific points and passes all others.\" },\r\n { id: 40, topic: \"Filters\", question: \"Which waveguide type typically supports guided light waves at optical frequencies?\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 41, topic: \"Audio and Recording\", question: \"Which of the following microphone works using the principle of capacitance variation with sound?\", options: [\"Carbon microphone\", \"Moving Coil microphone\", \"Ribbon microphone\", \"Condenser microphone\"], answer: 3, deleted: false, memoryTrick: \"Condenser = Capacitor.\", explanation: \"Condenser microphones use a diaphragm as one plate of a capacitor; sound waves change the distance between plates, altering capacitance.\" },\r\n { id: 42, topic: \"Audio and Recording\", question: \"The diaphragm of a moving coil microphone converts\", options: [\"Electrical energy into sound energy\", \"Sound pressure into mechanical movement\", \"Sound pressure into magnetic flux\", \"Light energy into electrical signal\"], answer: 1, deleted: false, memoryTrick: \"Diaphragm moves mechanically when sound hits it.\", explanation: \"The diaphragm reacts to acoustic pressure variations and translates them into physical (mechanical) vibrations of the attached coil.\" },\r\n { id: 43, topic: \"Audio and Recording\", question: \"Which of the following is true about the diaphragm in a dynamic cone type loudspeaker?<br>I. Made of paper, plastic or light metal.<br>II. Converts the motion of the voice coil into sound waves by vibrating air.<br>III. The narrow end (apex) of the cone is attached to the speaker frame.\", options: [\"I and II\", \"I, II and III\", \"II and III\", \"I and III\"], answer: 0, deleted: false, memoryTrick: \"Apex attaches to the voice coil, NOT the frame (the wide part attaches to the frame).\", explanation: \"Statements I and II are true. III is false because the apex connects to the voice coil, while the outer edge connects to the frame.\" },\r\n { id: 44, topic: \"Audio and Recording\", question: \"Which of the following statements are true?<br>I. Diaphragm of woofer is larger than midrange.<br>II. Powerful bass sounds are produced by tweeter.<br>III. The crossover network divides the signal into three frequency bands.\", options: [\"I and II\", \"I, II and III\", \"II and III\", \"I and III\"], answer: 3, deleted: false, memoryTrick: \"Tweeter = High pitches (birds tweet). Bass = Woofer (dogs woof).\", explanation: \"I is true (woofers need large surface areas for low frequencies). II is false (tweeters do highs). III is true for 3-way systems.\" },\r\n { id: 45, topic: \"Audio and Recording\", question: \"Which of the following statements are true? I. Rotation speed of a CD changes... etc.\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 46, topic: \"Antennas\", question: \"What is the gain of antenna with directivity of 10 and efficiency of 0.8?\", options: [\"8\", \"12.5\", \"10\", \"0.8\"], answer: 0, deleted: false, memoryTrick: \"Gain = Directivity \u00d7 Efficiency. 10 \u00d7 0.8 = 8.\", explanation: \"Antenna gain takes into account the resistive losses represented by radiation efficiency.\" },\r\n { id: 47, topic: \"Antennas\", question: \"Which of the following antenna that gives unidirectional radiation pattern?\", options: [\"End-fire array antenna\", \"Broadside array antenna\", \"Isotropic antenna\", \"Loop antenna\"], answer: 0, deleted: false, memoryTrick: \"Fire from the end = one direction.\", explanation: \"End-fire arrays radiate maximally along the axis of the array, producing a highly directional, unidirectional beam.\" },\r\n { id: 48, topic: \"Antennas\", question: \"Which of the following statements are false about a Yagi-Uda antenna used as receiver?<br>I. Driven element is used to receive feed power.<br>II. Director have a length equal to \u03bb\/2.<br>III. The parasitic elements in a Yagi-Uda antenna are directly connected to the transmission line.\", options: [\"I and II\", \"II and III\", \"I and III\", \"All of the above\"], answer: 1, deleted: false, memoryTrick: \"Directors are < \u03bb\/2. Parasitic = NO connection.\", explanation: \"Directors are roughly 5% shorter than \u03bb\/2. Parasitic elements (directors\/reflectors) are not electrically connected to the feedline.\" },\r\n { id: 49, topic: \"Ionospheric Propagation\", question: \"What is skip distance in ionospheric propagation?\", options: [\"Maximum possible range of sky wave\", \"Minimum distance from transmitter where sky wave is received\", \"Distance between two ionospheric layers\", \"Distance of ground reflection\"], answer: 1, deleted: false, memoryTrick: \"The dead zone it 'skips' over before landing.\", explanation: \"It's the shortest distance from the transmitter that a skywave returns to Earth at a given frequency.\" },\r\n { id: 50, topic: \"Ionospheric Propagation\", question: \"What is the MUF if the critical frequency of the F2 layer is 5 MHz and the angle of incidence is 60\u00b0?\", options: [\"2.5 MHz\", \"5 MHz\", \"7.5 MHz\", \"10 MHz\"], answer: 3, deleted: false, memoryTrick: \"MUF = fc \/ cos(\u03b8). 5 \/ cos(60) = 5 \/ 0.5 = 10.\", explanation: \"Using the secant law: MUF = fc * sec(\u03b8) = 5MHz * sec(60\u00b0) = 5 * 2 = 10 MHz.\" },\r\n { id: 51, topic: \"Amplitude Modulation (AM)\", question: \"Maximum transmission efficiency of amplitude modulation is\", options: [\"33.33%\", \"67.88%\", \"73%\", \"54.03%\"], answer: 0, deleted: false, memoryTrick: \"AM wastes 2\/3 of power in the carrier. Only 1\/3 (33%) is useful sidebands.\", explanation: \"At 100% modulation (m=1), carrier power is 2\/3 of total power, leaving 1\/3 (33.3%) for sidebands.\" },\r\n { id: 53, topic: \"Amplitude Modulation (AM)\", question: \"AM broadcast station transmits modulating frequency of 6 KHz. If carrier frequency is 820 KHz then frequency components in AM waves are\", options: [\"820 KHz only\", \"6 KHz, 820 KHz, 826 KHz\", \"820 KHz, 826 KHz, 814 KHz\", \"826 KHz, 814 KHz\"], answer: 2, deleted: false, memoryTrick: \"Carrier, Carrier+Msg, Carrier-Msg.\", explanation: \"AM contains the carrier (820), USB (820+6 = 826), and LSB (820-6 = 814).\" },\r\n { id: 54, topic: \"Amplitude Modulation (AM)\", question: \"The intermediate frequency of a superheterodyne receiver is 455 KHz. If it is tuned to 1500 KHz the image frequency will be\", options: [\"910 KHz\", \"2410 KHz\", \"1955 KHz\", \"1045 KHz\"], answer: 1, deleted: false, memoryTrick: \"Image = Signal + 2*IF. 1500 + 2(455) = 2410.\", explanation: \"The image frequency formula is fsi = fs + 2*IF.\" },\r\n { id: 55, topic: \"Amplitude Modulation (AM)\", question: \"The function of Compander in Communication system\", options: [\"Equalize SNR for both weak and strong signals\", \"Increase amplification of the signal\", \"Improve multiplexing\", \"Improve A\/D conversion\"], answer: 0, deleted: false, memoryTrick: \"Compand = Compress (strong) + Expand (weak).\", explanation: \"It compresses the dynamic range before transmission to boost weak signals over noise, then expands it at the receiver.\" },\r\n { id: 52, topic: \"Frequency Modulation (FM)\", question: \"The disadvantages of using balanced slope detector for demodulation of FM signal\", options: [\"The detector operates only for small deviation in frequency\", \"Low pass filter of the detector produces distortion in the detection\", \"Both A) and B)\", \"None of the above\"], answer: 2, deleted: false, memoryTrick: \"Slope detectors are non-linear and easily distorted.\", explanation: \"It relies on the non-linear skirts of tuned circuits, limiting linear operation to small deviations.\" },\r\n { id: 56, topic: \"Frequency Modulation (FM)\", question: \"A single tone 5 KHz message signal is sampled with 9 KHz, 7 KHz and 12 KHz. Aliasing effect will be seen in the reconstructed signal when signal is sampled at\", options: [\"7 KHz only\", \"7 KHz and 9 KHz\", \"12 KHz only\", \"7 KHz and 12 KHz\"], answer: 1, deleted: false, memoryTrick: \"Nyquist says sample > 2*MaxFreq. 2*5 = 10. Anything under 10 causes aliasing.\", explanation: \"Since Nyquist rate is 10 KHz, sampling at 7 KHz or 9 KHz violates the theorem and causes aliasing.\" },\r\n { id: 57, topic: \"Frequency Modulation (FM)\", question: \"Indirect method of FM generation<br>i. Does not require the carrier oscillator to respond directly to the modulating signal.<br>ii. Use frequency multiplication.<br>iii. Generate stable FM signal.<br>iv. It involves a crystal oscillator, a phase modulator and frequency multiplier.\", options: [\"Only i\", \"Only i and ii\", \"Only i, ii and iii\", \"All of the above (i, ii, iii and iv)\"], answer: 3, deleted: false, memoryTrick: \"Indirect (Armstrong) uses PM to get FM and needs multipliers.\", explanation: \"The Armstrong method integrates the message, phase modulates a stable crystal carrier, and uses frequency multipliers to achieve the desired deviation.\" },\r\n { id: 58, topic: \"Frequency Modulation (FM)\", question: \"The disadvantages of frequency modulation over amplitude modulation are\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 59, topic: \"Pulse Modulation\", question: \"A PAM signal can be detected using\", options: [\"High pass filter\", \"Low pass filter\", \"Band pass filter\", \"All pass filter\"], answer: 1, deleted: false, memoryTrick: \"Baseband signals hide in low frequencies.\", explanation: \"Pulse Amplitude Modulation (PAM) retains the baseband signal envelope, which can be extracted via a simple low pass filter.\" },\r\n { id: 60, topic: \"Pulse Modulation\", question: \"In Pulse Code Modulation if the number of quantization level is increased from 16 to 256 then the bandwidth requirement will approximately be\", options: [\"2 times\", \"4 times\", \"3 times\", \"16 times\"], answer: 0, deleted: false, memoryTrick: \"Levels go from 2^4 to 2^8. Bits double (4 to 8). BW doubles.\", explanation: \"Bandwidth in PCM is directly proportional to the number of bits (n). Since bits went from 4 to 8, bandwidth doubles.\" },\r\n { id: 61, topic: \"Monochrome Television\", question: \"Which modulation scheme is used in transmitting sound in the monochrome television transmission method?\", options: [\"AM\", \"FM\", \"PM\", \"QAM\"], answer: 1, deleted: false, memoryTrick: \"TV Picture is AM, TV Sound is FM.\", explanation: \"FM is used for sound due to its immunity to noise, which prevents video static from bleeding into the audio.\" },\r\n { id: 62, topic: \"Monochrome Television\", question: \"In a television transmission, which bandwidth-saving method is used in video modulation?\", options: [\"SSB\", \"VSB\", \"DSBSC\", \"DSBFC\"], answer: 1, deleted: false, memoryTrick: \"V = Video = Vestigial (VSB).\", explanation: \"Vestigial Sideband (VSB) transmits one full sideband and a 'vestige' of the other, saving bandwidth while retaining low-frequency video details.\" },\r\n { id: 65, topic: \"Monochrome Television\", question: \"Sound intermediate frequency in monochrome TV receivers in India is\", options: [\"38.9 MHz\", \"38.9 KHz\", \"33.4 MHz\", \"33.4 KHz\"], answer: 2, deleted: false, memoryTrick: \"Picture IF is 38.9, Sound IF is 33.4 (Difference is 5.5 MHz).\", explanation: \"In the CCIR system used in India, Picture IF is 38.9 MHz and Sound IF is 33.4 MHz.\" },\r\n { id: 63, topic: \"Colour Television\", question: \"Colour-killer, kills the colour when\", options: [\"Colour burst signal is present\", \"Colour burst signal is absent\", \"Colour is excessive\", \"Monochrome receiver is used\"], answer: 1, deleted: false, memoryTrick: \"No burst = no color signal = kill the color noise.\", explanation: \"The color killer circuit disables the chrominance amplifier during a monochrome broadcast to prevent colored 'confetti' noise on screen.\" },\r\n { id: 64, topic: \"Colour Television\", question: \"Which stages of the colour TV receiver controls contrast and brightness?\", options: [\"Video detector\", \"Comb filter\", \"Colour killer circuit\", \"Luminance amplifier\"], answer: 3, deleted: false, memoryTrick: \"Luminance = Luma = Y = Brightness.\", explanation: \"The luminance (Y) signal contains the black-and-white picture information, governing overall brightness and contrast.\" },\r\n { id: 66, topic: \"Radar Systems\", question: \"Blind speed problem in radar is avoided using\", options: [\"Use of mono pulse\", \"Increase the gain\", \"Vary the pulse repetition frequency\", \"Change the Doppler frequency\"], answer: 2, deleted: false, memoryTrick: \"Vary the PRF to 'stagger' the blindness.\", explanation: \"Blind speeds occur when the Doppler shift equals a multiple of the PRF. Using staggered (varying) PRF shifts the blind speeds.\" },\r\n { id: 67, topic: \"Radar Systems\", question: \"If the peak power of the radar is increased 16 times and other parameters are constant, the range of the radar is\", options: [\"Increased by 2 times\", \"Increased by 4 times\", \"Increased by 8 times\", \"Increased by 16 times\"], answer: 0, deleted: false, memoryTrick: \"Range is proportional to 4th root of Power. 16^(1\/4) = 2.\", explanation: \"According to the Radar Equation, Rmax depends on Pt^(1\/4). 16^(1\/4) = 2.\" },\r\n { id: 68, topic: \"Radar Systems\", question: \"Plan Position Indicator (PPI) displays\", options: [\"Amplitude of received echoes\", \"Map of the target area\", \"The target range, but not position\", \"The target position, but not range\"], answer: 1, deleted: false, memoryTrick: \"PPI is the classic sweeping circular radar screen you see in movies.\", explanation: \"PPI uses polar coordinates to display range and azimuth, creating a map-like 2D view of the target area.\" },\r\n { id: 69, topic: \"Optical Fiber Communication\", question: \"Dispersion is\", options: [\"Bending of light as it passes through an opening in an obstacle\", \"Light strikes a surface and is converted into heat\", \"Separating light into each of its component frequencies\", \"Light strike a substance which emits light at the same wavelength\"], answer: 2, deleted: false, memoryTrick: \"Dispersion disperses the colors (like a prism).\", explanation: \"Chromatic dispersion causes different wavelengths of a light pulse to travel at different speeds, broadening the pulse.\" },\r\n { id: 70, topic: \"Optical Fiber Communication\", question: \"Which optical detector provides internal amplification using impact ionisation?\", options: [\"Photo transistor\", \"PIN diode\", \"Avalanche photo diode\", \"Photo detector\"], answer: 2, deleted: false, memoryTrick: \"Avalanche = cascade of electrons (impact ionization).\", explanation: \"Avalanche Photodiodes (APDs) use high reverse bias to accelerate electrons, causing secondary emissions (impact ionization) and internal gain.\" },\r\n { id: 71, topic: \"ISDN\", question: \"In an ISDN Basic Rate Interface (BRI), signalling information between the user and network is managed through\", options: [\"B-channel\", \"D-channel\", \"Both B-channels alternately\", \"External control line\"], answer: 1, deleted: false, memoryTrick: \"B for Bearer (Data), D for Delta\/Data-link (Signaling).\", explanation: \"The 16 kbps D-channel is dedicated to out-of-band signaling and control for the two B-channels.\" },\r\n { id: 72, topic: \"Facsimile\", question: \"The 'Index of Cooperation (IOC)' in facsimile transmission relates to\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 73, topic: \"Facsimile\", question: \"Which recording method in a facsimile receiver gives high-quality reproduction and is often used in commercial fax machines?\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 74, topic: \"Digital Modulation\", question: \"A system transmits at a bit rate of 4 Mbps using raised cosine filtering with a roll-off factor of 0.25. The required minimum transmission bandwidth is approximately\", options: [\"2 MHz\", \"2.5 MHz\", \"3 MHz\", \"4 MHz\"], answer: 1, deleted: false, memoryTrick: \"BW = (Rb\/2) * (1 + alpha). 2 * 1.25 = 2.5.\", explanation: \"For baseband transmission, minimum Nyquist BW is Rb\/2. With roll-off, BW = (4\/2) * (1 + 0.25) = 2.5 MHz.\" },\r\n { id: 75, topic: \"Digital Modulation\", question: \"If the number of symbols transmitted per second in a digital communication system is increased while each symbol still represents the same number of bits, then\", options: [\"Bit rate remains constant but baud rate increases\", \"Both bit rate and baud rate increases\", \"Bit rate decreases but baud rate increases\", \"Bit rate increases but baud rate remains constant\"], answer: 1, deleted: false, memoryTrick: \"Baud rate = Symbols\/sec. Bit rate = Symbols\/sec * bits\/symbol.\", explanation: \"Since baud rate increases and bits\/symbol is constant, their product (bit rate) also increases.\" },\r\n { id: 76, topic: \"Digital Modulation\", question: \"For the Assertion (A) and Reason (R) given below, choose the correct alternative:<br>Assertion (A): Equalizers are used in digital systems to reduce Inter-Symbol Interference (ISI).<br>Reason (R): Equalizers modify the frequency response of the channel.\", options: [\"Both (A) and (R) are true and (R) correctly explains (A)\", \"Both (A) and (R) are true, but (R) does not explain (A)\", \"(A) is true, (R) is false\", \"Both (A) and (R) are false\"], answer: 0, deleted: false, memoryTrick: \"Equalize = flatten out the channel's flaws.\", explanation: \"Channel distortion causes ISI. Equalizers apply an inverse filter response to flatten the channel and cancel the ISI.\" },\r\n { id: 79, topic: \"Digital Modulation\", question: \"In an ASK demodulator, the envelope detector primarily\", options: [\"Recovers the carrier phase for synchronization\", \"Converts amplitude fluctuations into corresponding baseband signal\", \"Maintains constant envelope for improved SNR\", \"Reduces amplitude distortion caused by channel noise\"], answer: 1, deleted: false, memoryTrick: \"ASK is digital AM. Envelope detector grabs the amplitude.\", explanation: \"An envelope detector traces the amplitude outline of the ASK signal to recover the original baseband digital pulses.\" },\r\n { id: 80, topic: \"Digital Modulation\", question: \"Which of the following correctly describes a synchronous modem?\", options: [\"Requires separate clock line\", \"Transfers data in asynchronous blocks\", \"Does not use start\/stop bits\", \"Both A) and C)\"], answer: 3, deleted: false, memoryTrick: \"Synchronous = Synced by a clock, no need for start\/stop bumpers.\", explanation: \"Synchronous transmission relies on a shared clock signal to frame data, eliminating the overhead of start and stop bits used in asynchronous data.\" },\r\n { id: 77, topic: \"Error Detection and Coding\", question: \"Match the following digital codes with their descriptions:<br>a. Baudot code b. ASCII c. EBCDIC d. Hamming code<br>1. Text 7-bit code 2. Error correction code 3. Teleprinter 5-bit code 4. IBM 8-bit code\", options: [\"a \u2013 3, b \u2013 1, c \u2013 4, d \u2013 2\", \"a \u2013 1, b \u2013 4, c \u2013 3, d \u2013 2\", \"a \u2013 4, b \u2013 1, c \u2013 3, d \u2013 2\", \"a \u2013 3, b \u2013 2, c \u2013 1, d \u2013 4\"], answer: 0, deleted: false, memoryTrick: \"ASCII = 7-bit text. Hamming = Error.\", explanation: \"Baudot is an early 5-bit teleprinter code. ASCII is standard 7-bit. EBCDIC is IBM's 8-bit. Hamming corrects errors.\" },\r\n { id: 78, topic: \"Error Detection and Coding\", question: \"The minimum Hamming distance required to correct two errors and detect three is\", options: [\"3\", \"4\", \"5\", \"6\"], answer: 2, deleted: false, memoryTrick: \"dmin >= t + e + 1 (where e > t). dmin >= 2 + 3 + 1 = 6? Wait, dmin >= 2t+1 for correct 2 (dmin=5).\", explanation: \"To correct 't' errors: dmin >= 2t+1. So 2(2)+1 = 5. To detect 'e' errors: dmin >= e+1. 3+1 = 4. The larger requirement is 5.\" },\r\n { id: 81, topic: \"Satellite Communication\", question: \"Geostationary satellites are located approximately\", options: [\"3600 kilometers above the earth\", \"36000 kilometers above the earth\", \"600 kilometers above the earth\", \"400 kilometers above the earth\"], answer: 1, deleted: false, memoryTrick: \"GEO = 36,000 km.\", explanation: \"At ~35,786 km above the equator, the satellite's orbital period matches Earth's rotation (24 hours).\" },\r\n { id: 82, topic: \"Satellite Communication\", question: \"Kepler's third law states that\", options: [\"The orbit of a planet is an ellipse\", \"A line segment joining a planet and the sun sweeps out equal areas\", \"The cube of a planet's orbital period is proportional to the square of the length\", \"The square of a planet's orbital period is proportional to the cube of the length of the semi major axis\"], answer: 3, deleted: false, memoryTrick: \"T^2 is proportional to a^3 (Squares are Cubes).\", explanation: \"The square of the orbital period (T) is directly proportional to the cube of the semi-major axis (a).\" },\r\n { id: 83, topic: \"Satellite Communication\", question: \"The orbit which is below 1000 kilometer distance from the sea level is called\", options: [\"Medium Earth Orbit (MEO)\", \"High Earth Orbit (HEO)\", \"Low Earth Orbit (LEO)\", \"Geosynchronous Earth Orbit (GEO)\"], answer: 2, deleted: false, memoryTrick: \"Below 1000 = Low.\", explanation: \"Low Earth Orbit (LEO) generally ranges from 160 km to 2,000 km.\" },\r\n { id: 84, topic: \"Satellite Communication\", question: \"Closest distance of the satellite orbit to earth is\", options: [\"Perigee\", \"Apogee\", \"Skip distance\", \"Focal length\"], answer: 0, deleted: false, memoryTrick: \"Perigee = Perilously close. Apogee = Away.\", explanation: \"In an elliptical orbit, perigee is the point of closest approach to the central body.\" },\r\n { id: 85, topic: \"Satellite Communication\", question: \"Active satellites have\", options: [\"Power source\", \"Transponders\", \"Signal Processing Unit\", \"All of the above\"], answer: 3, deleted: false, memoryTrick: \"Active means it does work (amplifies\/processes), so it needs all these.\", explanation: \"Unlike passive reflectors, active satellites receive, amplify, process, and re-transmit signals using onboard power and transponders.\" },\r\n { id: 86, topic: \"Satellite Communication\", question: \"The sub system in satellite communication responsible for collecting data from on-board sensors to monitor the health and performance of a satellite is\", options: [\"Tracking sub system\", \"Command sub system\", \"Telemetry sub system\", \"Earth station\"], answer: 2, deleted: false, memoryTrick: \"Tele-metry = Measure from far away.\", explanation: \"Telemetry involves gathering sensor data (temperature, voltage, pressure) and transmitting it to Earth.\" },\r\n { id: 87, topic: \"Satellite Communication\", question: \"INTELSAT stands for\", options: [\"International Telecommunication Satellite\", \"Indian Telecommunication Satellite\", \"Inter Telecommunication Satellite\", \"None of the above\"], answer: 0, deleted: false, memoryTrick: \"INTEL = INTernational + TELecommunications.\", explanation: \"Formed in 1964 as the International Telecommunications Satellite Organization.\" },\r\n { id: 88, topic: \"Satellite Communication\", question: \"Geographical representation of satellite antenna radiation pattern is called\", options: [\"Spot\", \"Foot print\", \"Beam\", \"Region\"], answer: 1, deleted: false, memoryTrick: \"The footprint is where the satellite 'steps' its signal on Earth.\", explanation: \"A footprint is a map showing the contour lines of Equal Effective Isotropic Radiated Power (EIRP) covering the ground.\" },\r\n { id: 89, topic: \"Satellite Communication\", question: \"Which of the following is a satellite earth station antenna?\", options: [\"Helical antenna\", \"Toroidal antenna\", \"Yagi-Uda antenna\", \"Cassagrain antenna\"], answer: 3, deleted: false, memoryTrick: \"Cassagrain has a sub-reflector to easily mount heavy LNBs behind the dish.\", explanation: \"Cassegrain reflector antennas are widely used in earth stations because feed electronics can be mounted behind the main dish.\" },\r\n { id: 90, topic: \"Satellite Communication\", question: \"The unit which detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency is\", options: [\"Satellite receiver\", \"LNA\", \"Horn Antenna\", \"Dish\"], answer: 1, deleted: false, memoryTrick: \"Low Noise Amplifier\/Block (LNB\/LNA).\", explanation: \"The Low Noise Amplifier (often part of an LNB) grabs the weak microwave signal, amplifies it with minimal noise, and downconverts it.\" },\r\n { id: 91, topic: \"Cellular Concepts\", question: \"A simplified cellular telephone system primarily aims to\", options: [\"Increase base station size\", \"Enable frequency reuse across cells\", \"Eliminate all interference\", \"Use only wired connections\"], answer: 1, deleted: false, memoryTrick: \"Cellular means dividing areas into cells to reuse the same frequencies safely.\", explanation: \"Frequency reuse is the core concept of cellular networks, allowing limited spectrum to support unlimited subscribers.\" },\r\n { id: 92, topic: \"Cellular Concepts\", question: \"CDMA allows multiple users on the same frequency using\", options: [\"Unique codes\", \"Time slots\", \"Sectors\", \"Guard bands\"], answer: 0, deleted: false, memoryTrick: \"Code Division = Unique Codes.\", explanation: \"Code Division Multiple Access assigns unique spreading codes to users, allowing them to share the exact same frequency band simultaneously.\" },\r\n { id: 93, topic: \"Cellular Concepts\", question: \"Roaming in cellular systems allows\", options: [\"Fixed location calls only\", \"Users to move between different networks\", \"No handoff\", \"Satellite-only access\"], answer: 1, deleted: false, memoryTrick: \"Roaming = wandering into a different provider's territory.\", explanation: \"Roaming enables a mobile user to automatically connect to a visiting network when outside their home network's coverage.\" },\r\n { id: 94, topic: \"Cellular Concepts\", question: \"Improving coverage and capacity in cellular systems includes techniques like\", options: [\"Reducing frequency reuse\", \"Increasing tower height\", \"Cell splitting and sectoring\", \"Eliminating handoff\"], answer: 2, deleted: false, memoryTrick: \"Splitting makes smaller cells (more capacity). Sectoring uses directional antennas.\", explanation: \"Cell splitting increases channels per unit area. Sectoring reduces co-channel interference, allowing closer reuse.\" },\r\n { id: 95, topic: \"GSM\", question: \"In GSM, radio subsystem uses\", options: [\"Quadrature Phase Shift Keying (QPSK)\", \"Amplitude Shift Keying (ASK)\", \"CDMA\", \"Gaussian Minimum Shift Keying (GMSK)\"], answer: 3, deleted: false, memoryTrick: \"GSM uses GMSK.\", explanation: \"GMSK provides constant envelope modulation, which allows the use of highly efficient non-linear amplifiers in mobile devices.\" },\r\n { id: 96, topic: \"GSM\", question: \"For a cellular system with cluster size N = 7, if the total available channels are 395 and each cell is allocated the same number of channels, how many channels are available per cell?\", options: [\"50\", \"56\", \"65\", \"70\"], answer: 1, deleted: false, memoryTrick: \"395 \/ 7 = 56.42. Since you can't have half a channel, it's 56.\", explanation: \"Total channels \/ N. 395 \/ 7 = 56 channels per cell, leaving 3 channels unused.\" },\r\n { id: 97, topic: \"GSM\", question: \"The full form of GSM in the cellular service is\", options: [\"Global System for Mobile Communications\", \"General Mobile System\", \"Global Mobile Satellite\", \"None of the above\"], answer: 0, deleted: false, memoryTrick: \"Global System for Mobile.\", explanation: \"Originally Groupe Sp\u00e9cial Mobile, it was renamed Global System for Mobile Communications as it became an international standard.\" },\r\n { id: 98, topic: \"GSM\", question: \"In a hexagonal cellular system with a frequency reuse cluster size of 7, what is the co-channel reuse ratio (Q)?\", options: [\"3.65\", \"4.0\", \"4.58\", \"5.34\"], answer: 2, deleted: false, memoryTrick: \"Q = \u221a(3N). \u221a(3*7) = \u221a21 \u2248 4.58.\", explanation: \"The reuse ratio Q determines the spatial separation between co-channel cells relative to cell radius.\" },\r\n { id: 99, topic: \"GSM\", question: \"Which interference type is mitigated by proper channel assignment?\", options: [\"Co-Channel Interference\", \"Adjacent Channel Interference\", \"Both A) and B)\", \"Neither A) nor B)\"], answer: 2, deleted: false, memoryTrick: \"Assignment spacing fixes adjacent. Assignment location fixes co-channel.\", explanation: \"Geographic separation fixes co-channel interference, while frequency gaps (guard bands\/assignment) fix adjacent channel interference.\" },\r\n { id: 100, topic: \"GSM\", question: \"FDMA stands for\", options: [\"Frequency Division Multiple Access\", \"Frequency Domain Multiple Access\", \"Full Division Multiple Access\", \"Fixed Division Multiple Access\"], answer: 0, deleted: false, memoryTrick: \"Divide by Frequency.\", explanation: \"FDMA gives each user a discrete frequency slice of the spectrum.\" }\r\n ];\r\n\r\n var currentMode = 'learning';\r\n var currentFilter = 'All';\r\n var userAnswers = {};\r\n var individualAnswersVisible = {};\r\n var allAnswersRevealed = false;\r\n var testSubmitted = false;\r\n var showingOnlyWrong = false;\r\n var userVotes = {};\r\n var wrongQuestionIds = []; \r\n \r\n var isPremium = false;\r\n\r\n window.onload = function() {\r\n extractTopicsAndRenderFilters();\r\n renderQuestions();\r\n };\r\n\r\n function renderQuestions() {\r\n var container = document.getElementById('quiz-container');\r\n var htmlString = \"\";\r\n var visibleCount = 0;\r\n var currentTopicTracker = \"\";\r\n\r\n for (var i = 0; i < questionsData.length; i++) {\r\n var q = questionsData[i];\r\n\r\n if (currentFilter !== 'All' && q.topic !== currentFilter) {\r\n continue;\r\n }\r\n\r\n if (showingOnlyWrong) {\r\n if (wrongQuestionIds.indexOf(q.id) === -1) {\r\n continue; \r\n }\r\n }\r\n\r\n if (currentMode === 'attempt' && !isPremium && visibleCount >= 4) {\r\n htmlString += \"<div class='card paywall-card'>\";\r\n htmlString += \"<h2 style='color:var(--primary-color); margin-bottom:10px;'>\ud83d\udd12 Unlock Full Test<\/h2>\";\r\n htmlString += \"<p>You have completed the free preview of Attempt Mode.<\/p>\";\r\n htmlString += \"<p>Upgrade your account to unlock all 100 questions, see your final score, detailed reports, and access 'Reattempt Wrong Questions' features.<\/p>\";\r\n htmlString += \"<a href='YOUR_PAYMENT_LINK_HERE' class='paywall-btn'>Upgrade Now to Unlock All<\/a>\";\r\n htmlString += \"<\/div>\";\r\n break;\r\n }\r\n\r\n visibleCount++;\r\n\r\n if (q.topic !== currentTopicTracker) {\r\n htmlString += \"<h2 class='section-heading'>\" + q.topic + \"<\/h2>\";\r\n currentTopicTracker = q.topic;\r\n }\r\n\r\n htmlString += \"<div class='card' id='card-\" + q.id + \"'>\";\r\n htmlString += \"<div class='q-text'><strong>Q\" + visibleCount + \".<\/strong> \" + q.question + \"<\/div>\";\r\n \r\n htmlString += \"<div class='options-grid'>\";\r\n for (var j = 0; j < q.options.length; j++) {\r\n var optionLetter = String.fromCharCode(65 + j);\r\n var optionClass = \"option-item\";\r\n \r\n if (userAnswers[q.id] === j) optionClass += \" selected\";\r\n \r\n if (currentMode === 'attempt' && testSubmitted && !q.deleted) {\r\n if (q.answer === j) {\r\n optionClass += \" correct-opt\";\r\n } else if (userAnswers[q.id] === j && q.answer !== j) {\r\n optionClass += \" wrong-opt\";\r\n }\r\n }\r\n\r\n var clickAction = \"\";\r\n if (currentMode === 'attempt' && !testSubmitted) {\r\n clickAction = \"onclick='selectOption(\" + q.id + \", \" + j + \")'\";\r\n }\r\n\r\n htmlString += \"<div class='\" + optionClass + \"' \" + clickAction + \">\";\r\n htmlString += \"<strong>\" + optionLetter + \")<\/strong> \" + q.options[j];\r\n htmlString += \"<\/div>\";\r\n }\r\n htmlString += \"<\/div>\";\r\n\r\n if (currentMode === 'learning') {\r\n var btnText = individualAnswersVisible[q.id] ? \"Hide Answer\" : \"Show Answer\";\r\n htmlString += \"<button onclick='toggleSingleAnswer(\" + q.id + \")'>\" + btnText + \"<\/button>\";\r\n }\r\n\r\n var showAnsSection = false;\r\n if (currentMode === 'learning' && (allAnswersRevealed || individualAnswersVisible[q.id])) {\r\n showAnsSection = true;\r\n } else if (currentMode === 'attempt' && testSubmitted) {\r\n showAnsSection = true;\r\n }\r\n\r\n var ansDisplayStyle = showAnsSection ? \"display:block;\" : \"display:none;\";\r\n htmlString += \"<div class='answer-section' id='ans-section-\" + q.id + \"' style='\" + ansDisplayStyle + \"'>\";\r\n \r\n htmlString += \"<div class='ans-reveal'>\";\r\n if (q.deleted) {\r\n htmlString += \"<span class='deleted-text'>Deleted \u2014 no official answer<\/span>\";\r\n } else {\r\n var correctLetter = String.fromCharCode(65 + q.answer);\r\n htmlString += \"<span class='correct-text'>Correct Answer: \" + correctLetter + \") \" + q.options[q.answer] + \" \u2705<\/span>\";\r\n }\r\n htmlString += \"<\/div>\";\r\n\r\n if (!q.deleted && currentMode === 'attempt' && testSubmitted) {\r\n htmlString += \"<div class='disclaimer'><i>This Memory Trick is AI generated. Verify with standard sources.<\/i><\/div>\";\r\n htmlString += \"<div class='memory-trick'>\ud83e\udde0 <strong>Memory Trick:<\/strong> \" + q.memoryTrick + \"<\/div>\";\r\n htmlString += \"<div class='disclaimer'><i>This explanation all are user generated. Verify with standard sources.<\/i><\/div>\";\r\n htmlString += \"<div class='explanation'>\ud83d\udcd6 <strong>Explanation:<\/strong> \" + q.explanation + \"<\/div>\";\r\n\r\n var upVotes = userVotes[q.id] === 'up' ? 1 : 0;\r\n var downVotes = userVotes[q.id] === 'down' ? 1 : 0;\r\n \r\n htmlString += \"<div class='interaction-bar'>\";\r\n htmlString += \"<span>Helpful? \";\r\n htmlString += \"<button class='vote-btn' onclick='castVote(\" + q.id + \", \\\"up\\\")'>\ud83d\udc4d \" + upVotes + \"<\/button> \";\r\n htmlString += \"<button class='vote-btn' onclick='castVote(\" + q.id + \", \\\"down\\\")'>\ud83d\udc4e \" + downVotes + \"<\/button>\";\r\n htmlString += \"<\/span>\";\r\n htmlString += \"<span style='margin-left:15px;'>Difficulty: <select><option>Easy<\/option><option>Medium<\/option><option>Hard<\/option><\/select><\/span>\";\r\n htmlString += \"<button class='report-btn' onclick='alert(\\\"Thank you! Error reported to admin.\\\")'>Report Error<\/button>\";\r\n htmlString += \"<\/div>\";\r\n }\r\n\r\n htmlString += \"<\/div>\";\r\n htmlString += \"<\/div>\";\r\n }\r\n\r\n container.innerHTML = htmlString;\r\n document.getElementById('question-counter').innerText = \"Showing \" + visibleCount + \" questions\";\r\n }\r\n\r\n function setMode(mode) {\r\n currentMode = mode;\r\n testSubmitted = false;\r\n showingOnlyWrong = false;\r\n wrongQuestionIds = []; \r\n userAnswers = {};\r\n individualAnswersVisible = {};\r\n allAnswersRevealed = false;\r\n\r\n document.getElementById('btn-mode-learning').className = mode === 'learning' ? 'active-btn' : '';\r\n document.getElementById('btn-mode-attempt').className = mode === 'attempt' ? 'active-btn' : '';\r\n \r\n document.getElementById('btn-toggle-all').style.display = mode === 'learning' ? 'inline-block' : 'none';\r\n document.getElementById('submit-fab').style.display = mode === 'attempt' ? 'block' : 'none';\r\n document.getElementById('results-panel').style.display = 'none';\r\n document.getElementById('score-display').style.display = 'none';\r\n\r\n document.getElementById('filter-buttons').style.display = mode === 'learning' ? 'flex' : 'none';\r\n\r\n if (mode === 'attempt') {\r\n currentFilter = 'All';\r\n var selectMenu = document.getElementById('topic-select');\r\n if (selectMenu) {\r\n selectMenu.value = 'All';\r\n }\r\n }\r\n\r\n renderQuestions();\r\n }\r\n\r\n function extractTopicsAndRenderFilters() {\r\n var topics = [\"All\"];\r\n for (var i = 0; i < questionsData.length; i++) {\r\n if (topics.indexOf(questionsData[i].topic) === -1) {\r\n topics.push(questionsData[i].topic);\r\n }\r\n }\r\n\r\n var filterContainer = document.getElementById('filter-buttons');\r\n var html = \"<strong style='margin-right: 10px;'>Subject:<\/strong> <select id='topic-select' onchange='setFilter(this.value)'>\";\r\n for (var j = 0; j < topics.length; j++) {\r\n var selected = topics[j] === currentFilter ? \"selected\" : \"\";\r\n html += \"<option value='\" + topics[j] + \"' \" + selected + \">\" + topics[j] + \"<\/option>\";\r\n }\r\n html += \"<\/select>\";\r\n filterContainer.innerHTML = html;\r\n }\r\n\r\n function setFilter(topicName) {\r\n currentFilter = topicName;\r\n extractTopicsAndRenderFilters();\r\n renderQuestions();\r\n }\r\n\r\n function selectOption(questionId, optionIndex) {\r\n if (currentMode !== 'attempt' || testSubmitted) return;\r\n userAnswers[questionId] = optionIndex;\r\n renderQuestions();\r\n }\r\n\r\n function submitTest() {\r\n var score = 0;\r\n var totalValid = 0;\r\n var evaluatedCount = 0;\r\n wrongQuestionIds = []; \r\n\r\n for (var i = 0; i < questionsData.length; i++) {\r\n var q = questionsData[i];\r\n \r\n if (currentFilter !== 'All' && q.topic !== currentFilter) continue;\r\n if (showingOnlyWrong && (q.deleted || userAnswers[q.id] === q.answer)) continue;\r\n\r\n if (currentMode === 'attempt' && !isPremium && evaluatedCount >= 4) {\r\n break; \r\n }\r\n evaluatedCount++;\r\n\r\n if (!q.deleted) {\r\n totalValid++;\r\n if (userAnswers[q.id] === q.answer) {\r\n score++;\r\n } else {\r\n wrongQuestionIds.push(q.id);\r\n }\r\n }\r\n }\r\n\r\n testSubmitted = true;\r\n document.getElementById('submit-fab').style.display = 'none';\r\n \r\n document.getElementById('results-panel').style.display = 'block';\r\n document.getElementById('final-score-text').innerText = \"Score: \" + score + \" \/ \" + totalValid;\r\n \r\n var scoreDisp = document.getElementById('score-display');\r\n scoreDisp.style.display = 'inline-block';\r\n scoreDisp.innerText = \"Current Score: \" + score + \"\/\" + totalValid;\r\n\r\n window.scrollTo({ top: 0, behavior: 'smooth' });\r\n renderQuestions();\r\n }\r\n\r\n function reattemptWrong() {\r\n showingOnlyWrong = true;\r\n testSubmitted = false;\r\n \r\n for (var i = 0; i < wrongQuestionIds.length; i++) {\r\n delete userAnswers[wrongQuestionIds[i]];\r\n }\r\n\r\n document.getElementById('results-panel').style.display = 'none';\r\n document.getElementById('score-display').style.display = 'none';\r\n document.getElementById('submit-fab').style.display = 'block';\r\n \r\n renderQuestions();\r\n }\r\n\r\n function toggleSingleAnswer(questionId) {\r\n if (individualAnswersVisible[questionId]) {\r\n individualAnswersVisible[questionId] = false;\r\n } else {\r\n individualAnswersVisible[questionId] = true;\r\n }\r\n renderQuestions();\r\n }\r\n\r\n function toggleAllAnswers() {\r\n allAnswersRevealed = !allAnswersRevealed;\r\n var btn = document.getElementById('btn-toggle-all');\r\n btn.innerText = allAnswersRevealed ? \"Hide All Answers\" : \"Reveal All Answers\";\r\n individualAnswersVisible = {}; \r\n renderQuestions();\r\n }\r\n\r\n function castVote(questionId, type) {\r\n if (userVotes[questionId] === type) {\r\n delete userVotes[questionId];\r\n } else {\r\n userVotes[questionId] = type;\r\n }\r\n renderQuestions();\r\n }\r\n<\/script>\r\n<\/body>\r\n<\/html>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"pmpro_default_level":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-7","post","type-post","status-publish","format-standard","hentry","category-uncategorized","pmpro-has-access"],"_links":{"self":[{"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/posts\/7","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7"}],"version-history":[{"count":2,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/posts\/7\/revisions"}],"predecessor-version":[{"id":13,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/posts\/7\/revisions\/13"}],"wp:attachment":[{"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

{"id":7,"date":"2026-06-12T08:19:52","date_gmt":"2026-06-12T08:19:52","guid":{"rendered":"https:\/\/keralatechnicalpsc.com\/?p=7"},"modified":"2026-06-13T05:19:58","modified_gmt":"2026-06-13T05:19:58","slug":"operator","status":"publish","type":"post","link":"https:\/\/keralatechnicalpsc.com\/?p=7","title":{"rendered":"Operator"},"content":{"rendered":"\n\r\n\r\n\r\n \r\n \r\n Topic-Wise Categorized Question Bank<\/title>\r\n <style>\r\n :root {\r\n --primary-color: #0056b3;\r\n --primary-hover: #004494;\r\n --bg-color: #f4f7f6;\r\n --card-bg: #ffffff;\r\n --text-main: #333333;\r\n --text-muted: #666666;\r\n --border-color: #dddddd;\r\n --correct-color: #e6f4ea;\r\n --correct-text: #137333;\r\n --wrong-color: #fce8e6;\r\n --wrong-text: #c5221f;\r\n --deleted-text: #999999;\r\n }\r\n\r\n body {\r\n font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;\r\n background-color: var(--bg-color);\r\n color: var(--text-main);\r\n margin: 0;\r\n padding: 20px;\r\n line-height: 1.6;\r\n }\r\n\r\n .container {\r\n max-width: 800px;\r\n margin: 0 auto;\r\n }\r\n\r\n .header-controls {\r\n background: var(--card-bg);\r\n padding: 15px 20px;\r\n border-radius: 8px;\r\n box-shadow: 0 2px 4px rgba(0,0,0,0.05);\r\n margin-bottom: 20px;\r\n position: sticky;\r\n top: 10px;\r\n z-index: 100;\r\n }\r\n\r\n .mode-toggle, .filter-container {\r\n display: flex;\r\n flex-wrap: wrap;\r\n gap: 10px;\r\n margin-bottom: 10px;\r\n align-items: center;\r\n }\r\n\r\n button {\r\n padding: 8px 16px;\r\n border: 1px solid var(--primary-color);\r\n background: transparent;\r\n color: var(--primary-color);\r\n border-radius: 4px;\r\n cursor: pointer;\r\n font-size: 14px;\r\n transition: all 0.2s ease;\r\n }\r\n\r\n button:hover {\r\n background: #eef5ff;\r\n }\r\n\r\n button.active-btn {\r\n background: var(--primary-color);\r\n color: #fff;\r\n }\r\n\r\n select {\r\n padding: 8px;\r\n border: 1px solid var(--primary-color);\r\n border-radius: 4px;\r\n font-size: 14px;\r\n background: #fff;\r\n color: var(--primary-color);\r\n max-width: 100%;\r\n cursor: pointer;\r\n }\r\n\r\n .status-bar {\r\n display: flex;\r\n justify-content: space-between;\r\n font-size: 14px;\r\n color: var(--text-muted);\r\n border-top: 1px solid var(--border-color);\r\n padding-top: 10px;\r\n margin-top: 10px;\r\n }\r\n\r\n h1 {\r\n font-size: 24px;\r\n text-align: center;\r\n margin-bottom: 20px;\r\n color: var(--primary-color);\r\n }\r\n\r\n .section-heading {\r\n font-size: 18px;\r\n border-bottom: 2px solid var(--primary-color);\r\n padding-bottom: 5px;\r\n margin: 30px 0 15px 0;\r\n color: var(--primary-color);\r\n }\r\n\r\n .card {\r\n background: var(--card-bg);\r\n border-radius: 8px;\r\n padding: 20px;\r\n margin-bottom: 20px;\r\n box-shadow: 0 2px 5px rgba(0,0,0,0.05);\r\n transition: transform 0.2s ease;\r\n border: 1px solid var(--border-color);\r\n }\r\n \r\n .paywall-card {\r\n text-align: center;\r\n padding: 40px 20px;\r\n border: 2px dashed var(--primary-color);\r\n background: #f8fbff;\r\n }\r\n\r\n .paywall-btn {\r\n background: #28a745;\r\n color: #fff;\r\n font-size: 16px;\r\n padding: 12px 24px;\r\n border: none;\r\n border-radius: 30px;\r\n margin-top: 15px;\r\n font-weight: bold;\r\n box-shadow: 0 4px 6px rgba(0,0,0,0.1);\r\n display: inline-block;\r\n text-decoration: none;\r\n }\r\n \r\n .paywall-btn:hover {\r\n background: #218838;\r\n color: #fff;\r\n transform: translateY(-2px);\r\n }\r\n\r\n .q-text {\r\n font-size: 16px;\r\n font-weight: 500;\r\n margin-bottom: 15px;\r\n }\r\n\r\n .options-grid {\r\n display: grid;\r\n grid-template-columns: 1fr 1fr;\r\n gap: 10px;\r\n margin-bottom: 15px;\r\n }\r\n\r\n .option-item {\r\n padding: 10px;\r\n border: 1px solid var(--border-color);\r\n border-radius: 4px;\r\n cursor: pointer;\r\n background: #fafafa;\r\n transition: all 0.2s ease;\r\n }\r\n\r\n .option-item:hover {\r\n background: #f0f0f0;\r\n }\r\n\r\n .option-item.selected {\r\n border-color: var(--primary-color);\r\n background: #eef5ff;\r\n font-weight: bold;\r\n }\r\n\r\n .option-item.correct-opt {\r\n background: var(--correct-color);\r\n border-color: var(--correct-text);\r\n color: var(--correct-text);\r\n }\r\n\r\n .option-item.wrong-opt {\r\n background: var(--wrong-color);\r\n border-color: var(--wrong-text);\r\n color: var(--wrong-text);\r\n }\r\n\r\n .answer-section {\r\n display: none;\r\n margin-top: 15px;\r\n padding-top: 15px;\r\n border-top: 1px dashed var(--border-color);\r\n animation: fadeIn 0.3s ease;\r\n }\r\n\r\n @keyframes fadeIn {\r\n from { opacity: 0; transform: translateY(-5px); }\r\n to { opacity: 1; transform: translateY(0); }\r\n }\r\n\r\n .ans-reveal {\r\n font-weight: bold;\r\n margin-bottom: 10px;\r\n }\r\n\r\n .correct-text { color: var(--correct-text); }\r\n .deleted-text { color: var(--deleted-text); font-style: italic; }\r\n \r\n .disclaimer {\r\n font-size: 12px;\r\n color: #888;\r\n margin-top: 10px;\r\n margin-bottom: 2px;\r\n }\r\n\r\n .memory-trick {\r\n background: #fff8e1;\r\n padding: 10px;\r\n border-left: 4px solid #ffc107;\r\n border-radius: 4px;\r\n font-size: 14px;\r\n }\r\n\r\n .explanation {\r\n background: #e3f2fd;\r\n padding: 10px;\r\n border-left: 4px solid #2196f3;\r\n border-radius: 4px;\r\n font-size: 14px;\r\n margin-top: 10px;\r\n }\r\n\r\n .interaction-bar {\r\n margin-top: 15px;\r\n display: flex;\r\n flex-wrap: wrap;\r\n align-items: center;\r\n gap: 15px;\r\n font-size: 13px;\r\n }\r\n\r\n .vote-btn {\r\n padding: 4px 8px;\r\n font-size: 12px;\r\n border: 1px solid #ccc;\r\n color: #555;\r\n }\r\n\r\n .report-btn {\r\n color: var(--wrong-text);\r\n border-color: var(--wrong-text);\r\n margin-left: auto;\r\n }\r\n \r\n .report-btn:hover {\r\n background: var(--wrong-color);\r\n }\r\n\r\n #submit-fab {\r\n position: fixed;\r\n bottom: 30px;\r\n right: 30px;\r\n background: #28a745;\r\n color: white;\r\n border: none;\r\n padding: 15px 25px;\r\n font-size: 16px;\r\n font-weight: bold;\r\n border-radius: 30px;\r\n box-shadow: 0 4px 10px rgba(0,0,0,0.2);\r\n cursor: pointer;\r\n z-index: 1000;\r\n display: none;\r\n transition: transform 0.2s;\r\n }\r\n\r\n #submit-fab:hover {\r\n transform: scale(1.05);\r\n background: #218838;\r\n }\r\n\r\n .results-panel {\r\n background: var(--card-bg);\r\n padding: 20px;\r\n border-radius: 8px;\r\n margin-bottom: 20px;\r\n text-align: center;\r\n box-shadow: 0 2px 5px rgba(0,0,0,0.1);\r\n display: none;\r\n border: 2px solid var(--primary-color);\r\n }\r\n\r\n @media (max-width: 600px) {\r\n .options-grid { grid-template-columns: 1fr; }\r\n .interaction-bar { flex-direction: column; align-items: flex-start; }\r\n .report-btn { margin-left: 0; }\r\n }\r\n <\/style>\r\n<\/head>\r\n<body>\r\n\r\n<div class=\"container\">\r\n <h1>\ud83d\udcdd Topic-Wise Question Bank<\/h1>\r\n\r\n <div class=\"header-controls\">\r\n <div class=\"mode-toggle\">\r\n <strong>Mode:<\/strong>\r\n <button id=\"btn-mode-learning\" class=\"active-btn\" onclick=\"setMode('learning')\">\ud83d\udcd6 Learning Mode<\/button>\r\n <button id=\"btn-mode-attempt\" onclick=\"setMode('attempt')\">\u23f1\ufe0f Attempt Mode<\/button>\r\n <button id=\"btn-toggle-all\" onclick=\"toggleAllAnswers()\" style=\"margin-left: auto;\">Reveal All Answers<\/button>\r\n <\/div>\r\n \r\n <div class=\"filter-container\" id=\"filter-buttons\">\r\n <\/div>\r\n\r\n <div class=\"status-bar\">\r\n <span id=\"question-counter\">Showing 0 questions<\/span>\r\n <span id=\"score-display\" style=\"display:none; font-weight: bold; color: var(--primary-color);\"><\/span>\r\n <\/div>\r\n <\/div>\r\n\r\n <div id=\"results-panel\" class=\"results-panel\">\r\n <h2 id=\"final-score-text\">Score: 0 \/ 0<\/h2>\r\n <p>Review your answers below.<\/p>\r\n <button id=\"btn-reattempt\" onclick=\"reattemptWrong()\" style=\"background: var(--primary-color); color: white;\">\ud83d\udd04 Reattempt Wrong Questions<\/button>\r\n <\/div>\r\n\r\n <div id=\"quiz-container\"><\/div>\r\n <button id=\"submit-fab\" onclick=\"submitTest()\">Submit Test<\/button>\r\n<\/div>\r\n\r\n<script>\r\n var questionsData = [\r\n { id: 1, topic: \"PN Junction Diode\", question: \"Which among the following semiconductor materials exhibits the highest breakdown voltage in a PN junction diode for similar doping levels?\", options: [\"GaAs\", \"Ge\", \"Si\", \"GaN\"], answer: 3, deleted: false, memoryTrick: \"GaN = Giant Amount of eNergy.\", explanation: \"GaN (Gallium Nitride) is a wide-bandgap material, leading to much higher breakdown voltages.\" },\r\n { id: 2, topic: \"PN Junction Diode\", question: \"The dynamic resistance of a forward-biased PN diode increases with\", options: [\"Increasing the forward bias voltage\", \"Decreasing the DC bias current\", \"Increasing the doping concentration\", \"Reducing the temperature\"], answer: 1, deleted: false, memoryTrick: \"Dynamic resistance is inversely proportional to current (r = VT\/I).\", explanation: \"As DC bias current decreases, dynamic resistance increases.\" },\r\n { id: 3, topic: \"PN Junction Diode\", question: \"Zener and Avalanche breakdown phenomena display opposite temperature coefficients because\", options: [\"Zener breakdown has a negative temperature coefficient, while Avalanche breakdown has a positive temperature coefficient\", \"Zener breakdown has a positive temperature coefficient, while Avalanche breakdown has a negative temperature coefficient\", \"Both have positive temperature coefficients\", \"Both have negative temperature coefficients\"], answer: 0, deleted: false, memoryTrick: \"Zener = Zero or sub-zero (negative). Avalanche = Adds up (positive).\", explanation: \"Zener breakdown voltage decreases with temperature (negative), while Avalanche increases (positive).\" },\r\n { id: 4, topic: \"PN Junction Diode\", question: \"For semiconductor diodes, the barrier potential decreases by approximately\", options: [\"2 mV for each \u00b0C rise in temperature\", \"2 mV for each \u00b0C drop in temperature\", \"0.7 mV for each \u00b0C rise in temperature\", \"2 V for each \u00b0C rise in temperature\"], answer: 0, deleted: false, memoryTrick: \"Hotter diode = barrier drops by 2mV\/\u00b0C.\", explanation: \"As temperature rises, intrinsic carrier concentration increases, reducing the barrier potential by roughly 2-2.5 mV\/\u00b0C.\" },\r\n { id: 5, topic: \"Rectifiers and Voltage Multipliers\", question: \"The average value of a half wave rectifier is\", options: [\"2 Vm\/\u03c0\", \"Vm\/\u03c0\", \"Vm\/2\", \"Vm\/\u221a2\"], answer: 1, deleted: false, memoryTrick: \"Half wave = one \u03c0. Full wave = two \u03c0s.\", explanation: \"Integrating a sine wave over a half cycle gives Vm\/\u03c0.\" },\r\n { id: 9, topic: \"Rectifiers and Voltage Multipliers\", question: \"Poor voltage regulation in voltage doublers can be improved with\", options: [\"Increasing input frequency\", \"Using smaller capacitors\", \"Reducing diode forward voltage\", \"Using large value capacitors\"], answer: 3, deleted: false, memoryTrick: \"Bigger caps = Better regulation.\", explanation: \"Larger capacitors store more charge, reducing ripple and improving voltage regulation.\" },\r\n { id: 6, topic: \"Optoelectronic Devices\", question: \"The switching time of an opto coupler decreases with\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 7, topic: \"Optoelectronic Devices\", question: \"Which parameter in a solar cell ensures the maximum number of photons of light energy reach the p-n junction?\", options: [\"High series resistance\", \"Anti Reflective Coating (ARC) and surface texturing\", \"Thick glass cover\", \"High doping concentration\"], answer: 1, deleted: false, memoryTrick: \"ARC traps the light.\", explanation: \"Anti-reflective coating minimizes light bouncing off the surface, maximizing absorption.\" },\r\n { id: 8, topic: \"Optoelectronic Devices\", question: \"Which material is most commonly used in Light Dependent Resistors (LDRs) due to its high photosensitivity in the visible spectrum?\", options: [\"Cadmium Sulphide (CdS)\", \"Silicon (Si)\", \"Germanium (Ge)\", \"Gallium Arsenide (GaAs)\"], answer: 0, deleted: false, memoryTrick: \"CdS = Catches Daylight Swiftly.\", explanation: \"CdS has a spectral response similar to the human eye, making it ideal for visible light LDRs.\" },\r\n { id: 10, topic: \"Optoelectronic Devices\", question: \"The output current in a phototransistor depends on\", options: [\"Temperature\", \"Reverse saturation current\", \"Light intensity\", \"Collector-emitter voltage\"], answer: 2, deleted: false, memoryTrick: \"Photo = Light. Current depends on light.\", explanation: \"The base current is generated by photons, so output collector current is directly proportional to light intensity.\" },\r\n { id: 11, topic: \"Bipolar Junction Transistor (BJT)\", question: \"In a transistor amplifier circuit negative feedback __________ amplifier bandwidth.\", options: [\"Decreases\", \"Increases\", \"Narrow\", \"No change\"], answer: 1, deleted: false, memoryTrick: \"Feedback trades gain for bandwidth (bandwidth increases).\", explanation: \"Negative feedback flattens frequency response, extending upper and lower cut-off frequencies.\" },\r\n { id: 12, topic: \"Bipolar Junction Transistor (BJT)\", question: \"Fixed biasing circuit RB = 330 K ohm, RC = 15.5 K ohm, VCC = 12 V and IC = 3 mA. Determine VCE.\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 13, topic: \"Bipolar Junction Transistor (BJT)\", question: \"In transistor configuration how \u03b2 of a transistor is related to its \u03b1?\", options: [\"\u03b2 = \u03b1 \/ \u03b1 + 1\", \"\u03b2 = \u03b1 \/ 1 \u2013 \u03b1\", \"\u03b1 = \u03b2 \/ 1 \u2013 \u03b2\", \"\u03b1 = \u03b2 \/ \u03b2 \u2013 1\"], answer: 1, deleted: false, memoryTrick: \"\u03b2 is bigger than \u03b1, so divide \u03b1 by a number less than 1 (1 - \u03b1).\", explanation: \"Beta is the common-emitter current gain, Alpha is common-base. \u03b2 = \u03b1\/(1-\u03b1).\" },\r\n { id: 14, topic: \"Bipolar Junction Transistor (BJT)\", question: \"An RC coupled amplifier has a voltage gain of 100 in the frequency range of 500 \u2013 20 KHz. Calculate gain in dB.\", options: [\"10\", \"100\", \"40\", \"80\"], answer: 2, deleted: false, memoryTrick: \"dB = 20 * log10(Voltage Gain). 20 * log10(100) = 20 * 2 = 40.\", explanation: \"Voltage gain in dB is 20 * log(100) = 40 dB.\" },\r\n { id: 15, topic: \"Field Effect Transistor (FET)\", question: \"Field Effect Transistor (FET) is a ________ device.\", options: [\"Voltage Control\", \"Current Control\", \"Voltage and Current Control\", \"None of the above\"], answer: 0, deleted: false, memoryTrick: \"Field = Voltage.\", explanation: \"The gate-source voltage controls the drain current, drawing practically zero gate current.\" },\r\n { id: 17, topic: \"Field Effect Transistor (FET)\", question: \"Change in Gate to Source voltage of FET is 1 Volt and Change in drain current is 1.5 mA. Determine the magnitude of transconductance.\", options: [\"1.5 mS\", \"0.5 mS\", \"2 mS\", \"2.5 mS\"], answer: 0, deleted: false, memoryTrick: \"gm = \u0394Id \/ \u0394Vgs. 1.5 \/ 1 = 1.5.\", explanation: \"Transconductance is the ratio of change in drain current to change in gate-source voltage.\" },\r\n { id: 18, topic: \"Field Effect Transistor (FET)\", question: \"MOSFET's have an important property that they can be used as\", options: [\"A Resistor\", \"A Capacitor\", \"An Amplifier\", \"All of the above\"], answer: 3, deleted: false, memoryTrick: \"MOSFETs do it all.\", explanation: \"MOSFETs can act as voltage-controlled resistors (linear region), capacitors (gate oxide), and amplifiers (saturation region).\" },\r\n { id: 19, topic: \"Unijunction Transistor (UJT)\", question: \"When emitter terminal of a Unijunction Transistor (UJT) is open the resistance of the base terminal is\", options: [\"Very low\", \"Very high\", \"Low\", \"Moderate\"], answer: 1, deleted: false, memoryTrick: \"Open emitter = basically just a chunk of lightly doped silicon = High resistance.\", explanation: \"Without emitter current, the interbase resistance (RBB) is typically high (5k - 10k ohms).\" },\r\n { id: 20, topic: \"Unijunction Transistor (UJT)\", question: \"VI Characteristics of a Unijunction Transistor (UJT), the region between the peak point and valley point is called\", options: [\"Saturation Region\", \"Cut-off Region\", \"Negative Resistance Region\", \"Peak Point Voltage\"], answer: 2, deleted: false, memoryTrick: \"Voltage drops while current rises = Negative Resistance.\", explanation: \"In this region, increasing current results in decreasing voltage, characteristic of negative resistance devices.\" },\r\n { id: 16, topic: \"Oscillators\", question: \"Which of the following oscillator provides high accuracy of oscillation?\", options: [\"Wein Bridge Oscillator\", \"Colpits Oscillator\", \"Hartley Oscillator\", \"Crystal Oscillator\"], answer: 3, deleted: false, memoryTrick: \"Crystals are precise (think quartz watches).\", explanation: \"Crystal oscillators use the piezoelectric effect of a quartz crystal, providing extremely stable and accurate frequencies.\" },\r\n { id: 21, topic: \"Operational Amplifiers\", question: \"Slew rate limits the op-amp's performance at\", options: [\"DC\", \"Low frequency\", \"High frequency\", \"Zero\"], answer: 2, deleted: false, memoryTrick: \"Slew = Speed. High speed = High frequency.\", explanation: \"Slew rate is the maximum rate of change of output voltage, which restricts high-frequency performance.\" },\r\n { id: 22, topic: \"Operational Amplifiers\", question: \"A Schmidt trigger circuit using an op-amp is mainly used for\", options: [\"Amplifying analog signals\", \"Converting analog signals to digital pulses\", \"Frequency multiplication\", \"Phase shifting\"], answer: 1, deleted: false, memoryTrick: \"Trigger = Snap to Digital.\", explanation: \"It uses positive feedback to snap between two states, turning noisy analog signals into clean digital square waves.\" },\r\n { id: 24, topic: \"Operational Amplifiers\", question: \"In an op-amp differentiator circuit, the input element is\", options: [\"Diode\", \"Transistor\", \"Capacitor\", \"Inductor\"], answer: 2, deleted: false, memoryTrick: \"Differentiator = Capacitor first (DC). Integrator = Resistor first.\", explanation: \"The capacitor is in series with the input, producing an output proportional to the derivative of the input voltage.\" },\r\n { id: 23, topic: \"555 Timer\", question: \"In the functional block diagram of 555 timer, the discharge transistor is\", options: [\"PNP transistor connected to Vcc\", \"NPN transistor connected to ground\", \"FET connected to threshold pin\", \"PNP connected to control pin\"], answer: 1, deleted: false, memoryTrick: \"Discharge = Dump to ground via NPN.\", explanation: \"Pin 7 connects to the open collector of an NPN transistor, which discharges the external timing capacitor to ground.\" },\r\n { id: 25, topic: \"Voltage Regulators\", question: \"LM317 has how many pins?\", options: [\"2\", \"3\", \"4\", \"8\"], answer: 1, deleted: false, memoryTrick: \"LM317 = 3 pins (Adj, Vout, Vin).\", explanation: \"It's a standard 3-terminal adjustable voltage regulator.\" },\r\n { id: 26, topic: \"DAC and ADC\", question: \"The reference voltage (Vref) in a DAC is used to\", options: [\"Set the output voltage range\", \"Stabilize the input\", \"Reduce power\", \"Control clock frequency\"], answer: 0, deleted: false, memoryTrick: \"Reference = Scale size.\", explanation: \"Vref determines the maximum analog output voltage when all digital bits are 1.\" },\r\n { id: 27, topic: \"DAC and ADC\", question: \"The output impedance of an ideal R\u20132R ladder DAC is\", options: [\"R\", \"2R\", \"R\/2\", \"Infinite\"], answer: 0, deleted: false, memoryTrick: \"Look back into the ladder, it always equals R.\", explanation: \"By Thevenin's theorem, looking into any node of an infinite R-2R ladder yields an equivalent resistance of R.\" },\r\n { id: 28, topic: \"DAC and ADC\", question: \"The accuracy of ramp-type ADC mainly depends on\", options: [\"Clock frequency and ramp linearity\", \"Comparator gain\", \"Input resistance\", \"Counter type\"], answer: 0, deleted: false, memoryTrick: \"Ramp depends on time (clock) and slope (linearity).\", explanation: \"A steady clock and a perfectly linear ramp voltage are required for accurate time-to-voltage conversion.\" },\r\n { id: 29, topic: \"DAC and ADC\", question: \"A higher number of bits in an ADC gives\", options: [\"Lower resolution\", \"Higher resolution\", \"Slower conversion\", \"Lower accuracy\"], answer: 1, deleted: false, memoryTrick: \"More bits = more details = higher resolution.\", explanation: \"Resolution is 2^n. More bits mean smaller step sizes and greater precision.\" },\r\n { id: 30, topic: \"DAC and ADC\", question: \"The conversion time of a successive approximation ADC depends on\", options: [\"Input voltage magnitude\", \"Step size\", \"Number of bits and clock frequency\", \"None of these\"], answer: 2, deleted: false, memoryTrick: \"SAR takes exactly 'N' clock cycles for 'N' bits.\", explanation: \"It requires one clock cycle per bit of resolution, regardless of the input voltage.\" },\r\n { id: 31, topic: \"Two-Port Networks\", question: \"Which impedance is defined as the impedance seen looking into the network with the other end terminated by the same impedance?\", options: [\"Iterative impedance\", \"Characteristic impedance\", \"Input impedance\", \"Output impedance\"], answer: 0, deleted: false, memoryTrick: \"Iterative = Repeating the same impedance.\", explanation: \"Iterative impedance is the impedance that, when connected to one port, presents the same impedance at the other port.\" },\r\n { id: 32, topic: \"Two-Port Networks\", question: \"For symmetrical T networks, the characteristic impedance is\", options: [\"Arithmetic mean of open and short circuit impedances\", \"Geometric mean of open and short circuit impedances\", \"Sum of all impedances\", \"Difference of all impedances\"], answer: 1, deleted: false, memoryTrick: \"Z0 = \u221a(Zoc * Zsc). Root = Geometric mean.\", explanation: \"Characteristic impedance is the square root of the product of open-circuit and short-circuit impedances.\" },\r\n { id: 33, topic: \"Transmission Lines\", question: \"Which of the following affects the characteristic impedance Z0 of a lossless transmission line?\", options: [\"Only resistance R\", \"Only inductance L and capacitance C\", \"Conductance G only\", \"Frequency only\"], answer: 1, deleted: false, memoryTrick: \"Lossless means R=0, G=0. So only L and C remain.\", explanation: \"For a lossless line, Z0 = \u221a(L\/C).\" },\r\n { id: 38, topic: \"Transmission Lines\", question: \"Standing waves occur on a transmission line due to\", options: [\"Perfectly matched load\", \"Reflections caused by load mismatch\", \"High voltage at the source\", \"Infinite line length\"], answer: 1, deleted: false, memoryTrick: \"Waves stand when they crash back (reflect).\", explanation: \"When load impedance doesn't match line impedance, energy reflects back, interfering with the forward wave to create standing waves.\" },\r\n { id: 39, topic: \"Transmission Lines\", question: \"If SWR is greater than 1, it indicates\", options: [\"No reflected wave\", \"Presence of reflected wave leading to standing waves\", \"Power supply failure\", \"Perfect transmission line operation\"], answer: 1, deleted: false, memoryTrick: \"SWR = 1 is perfect. >1 means reflection.\", explanation: \"Standing Wave Ratio (SWR) > 1 means the reflection coefficient is non-zero, indicating a mismatch.\" },\r\n { id: 34, topic: \"Attenuators and Equalizers\", question: \"A constant resistance equalizer typically results in\", options: [\"Variable input impedance\", \"Constant input impedance over frequency range\", \"Variable power loss\", \"No frequency shaping\"], answer: 1, deleted: false, memoryTrick: \"Name says it all: Constant Resistance.\", explanation: \"It provides a constant resistive input impedance at all frequencies, preventing reflections.\" },\r\n { id: 35, topic: \"Attenuators and Equalizers\", question: \"Which parameter is critical for designing attenuator resistor values in T and Pi networks?\", options: [\"Voltage swing\", \"Frequency of operation\", \"Characteristic impedance and attenuation level\", \"Temperature coefficient\"], answer: 2, deleted: false, memoryTrick: \"You need to know how much to attenuate (dB) and the line impedance (Z0).\", explanation: \"Design formulas require the desired attenuation in dB (or N) and the system's characteristic impedance (Ro).\" },\r\n { id: 36, topic: \"Attenuators and Equalizers\", question: \"What is the benefit of a Pi-pad attenuator over a T-pad attenuator?\", options: [\"Uses fewer components\", \"Better impedance matching at high frequencies\", \"Simpler design\", \"Higher power amplification\"], answer: 1, deleted: false, memoryTrick: \"Pi handles high freq capacitance better.\", explanation: \"At RF frequencies, shunt capacitances are easier to absorb into the parallel arms of a Pi network.\" },\r\n { id: 37, topic: \"Filters\", question: \"A filter designed to eliminate frequencies in a specific range while allowing others to pass is called\", options: [\"Band-pass filter\", \"Band-stop filter\", \"Low-pass filter\", \"High-pass filter\"], answer: 1, deleted: false, memoryTrick: \"Stops a specific band.\", explanation: \"A band-stop (or notch) filter rejects frequencies between two specific points and passes all others.\" },\r\n { id: 40, topic: \"Filters\", question: \"Which waveguide type typically supports guided light waves at optical frequencies?\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 41, topic: \"Audio and Recording\", question: \"Which of the following microphone works using the principle of capacitance variation with sound?\", options: [\"Carbon microphone\", \"Moving Coil microphone\", \"Ribbon microphone\", \"Condenser microphone\"], answer: 3, deleted: false, memoryTrick: \"Condenser = Capacitor.\", explanation: \"Condenser microphones use a diaphragm as one plate of a capacitor; sound waves change the distance between plates, altering capacitance.\" },\r\n { id: 42, topic: \"Audio and Recording\", question: \"The diaphragm of a moving coil microphone converts\", options: [\"Electrical energy into sound energy\", \"Sound pressure into mechanical movement\", \"Sound pressure into magnetic flux\", \"Light energy into electrical signal\"], answer: 1, deleted: false, memoryTrick: \"Diaphragm moves mechanically when sound hits it.\", explanation: \"The diaphragm reacts to acoustic pressure variations and translates them into physical (mechanical) vibrations of the attached coil.\" },\r\n { id: 43, topic: \"Audio and Recording\", question: \"Which of the following is true about the diaphragm in a dynamic cone type loudspeaker?<br>I. Made of paper, plastic or light metal.<br>II. Converts the motion of the voice coil into sound waves by vibrating air.<br>III. The narrow end (apex) of the cone is attached to the speaker frame.\", options: [\"I and II\", \"I, II and III\", \"II and III\", \"I and III\"], answer: 0, deleted: false, memoryTrick: \"Apex attaches to the voice coil, NOT the frame (the wide part attaches to the frame).\", explanation: \"Statements I and II are true. III is false because the apex connects to the voice coil, while the outer edge connects to the frame.\" },\r\n { id: 44, topic: \"Audio and Recording\", question: \"Which of the following statements are true?<br>I. Diaphragm of woofer is larger than midrange.<br>II. Powerful bass sounds are produced by tweeter.<br>III. The crossover network divides the signal into three frequency bands.\", options: [\"I and II\", \"I, II and III\", \"II and III\", \"I and III\"], answer: 3, deleted: false, memoryTrick: \"Tweeter = High pitches (birds tweet). Bass = Woofer (dogs woof).\", explanation: \"I is true (woofers need large surface areas for low frequencies). II is false (tweeters do highs). III is true for 3-way systems.\" },\r\n { id: 45, topic: \"Audio and Recording\", question: \"Which of the following statements are true? I. Rotation speed of a CD changes... etc.\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 46, topic: \"Antennas\", question: \"What is the gain of antenna with directivity of 10 and efficiency of 0.8?\", options: [\"8\", \"12.5\", \"10\", \"0.8\"], answer: 0, deleted: false, memoryTrick: \"Gain = Directivity \u00d7 Efficiency. 10 \u00d7 0.8 = 8.\", explanation: \"Antenna gain takes into account the resistive losses represented by radiation efficiency.\" },\r\n { id: 47, topic: \"Antennas\", question: \"Which of the following antenna that gives unidirectional radiation pattern?\", options: [\"End-fire array antenna\", \"Broadside array antenna\", \"Isotropic antenna\", \"Loop antenna\"], answer: 0, deleted: false, memoryTrick: \"Fire from the end = one direction.\", explanation: \"End-fire arrays radiate maximally along the axis of the array, producing a highly directional, unidirectional beam.\" },\r\n { id: 48, topic: \"Antennas\", question: \"Which of the following statements are false about a Yagi-Uda antenna used as receiver?<br>I. Driven element is used to receive feed power.<br>II. Director have a length equal to \u03bb\/2.<br>III. The parasitic elements in a Yagi-Uda antenna are directly connected to the transmission line.\", options: [\"I and II\", \"II and III\", \"I and III\", \"All of the above\"], answer: 1, deleted: false, memoryTrick: \"Directors are < \u03bb\/2. Parasitic = NO connection.\", explanation: \"Directors are roughly 5% shorter than \u03bb\/2. Parasitic elements (directors\/reflectors) are not electrically connected to the feedline.\" },\r\n { id: 49, topic: \"Ionospheric Propagation\", question: \"What is skip distance in ionospheric propagation?\", options: [\"Maximum possible range of sky wave\", \"Minimum distance from transmitter where sky wave is received\", \"Distance between two ionospheric layers\", \"Distance of ground reflection\"], answer: 1, deleted: false, memoryTrick: \"The dead zone it 'skips' over before landing.\", explanation: \"It's the shortest distance from the transmitter that a skywave returns to Earth at a given frequency.\" },\r\n { id: 50, topic: \"Ionospheric Propagation\", question: \"What is the MUF if the critical frequency of the F2 layer is 5 MHz and the angle of incidence is 60\u00b0?\", options: [\"2.5 MHz\", \"5 MHz\", \"7.5 MHz\", \"10 MHz\"], answer: 3, deleted: false, memoryTrick: \"MUF = fc \/ cos(\u03b8). 5 \/ cos(60) = 5 \/ 0.5 = 10.\", explanation: \"Using the secant law: MUF = fc * sec(\u03b8) = 5MHz * sec(60\u00b0) = 5 * 2 = 10 MHz.\" },\r\n { id: 51, topic: \"Amplitude Modulation (AM)\", question: \"Maximum transmission efficiency of amplitude modulation is\", options: [\"33.33%\", \"67.88%\", \"73%\", \"54.03%\"], answer: 0, deleted: false, memoryTrick: \"AM wastes 2\/3 of power in the carrier. Only 1\/3 (33%) is useful sidebands.\", explanation: \"At 100% modulation (m=1), carrier power is 2\/3 of total power, leaving 1\/3 (33.3%) for sidebands.\" },\r\n { id: 53, topic: \"Amplitude Modulation (AM)\", question: \"AM broadcast station transmits modulating frequency of 6 KHz. If carrier frequency is 820 KHz then frequency components in AM waves are\", options: [\"820 KHz only\", \"6 KHz, 820 KHz, 826 KHz\", \"820 KHz, 826 KHz, 814 KHz\", \"826 KHz, 814 KHz\"], answer: 2, deleted: false, memoryTrick: \"Carrier, Carrier+Msg, Carrier-Msg.\", explanation: \"AM contains the carrier (820), USB (820+6 = 826), and LSB (820-6 = 814).\" },\r\n { id: 54, topic: \"Amplitude Modulation (AM)\", question: \"The intermediate frequency of a superheterodyne receiver is 455 KHz. If it is tuned to 1500 KHz the image frequency will be\", options: [\"910 KHz\", \"2410 KHz\", \"1955 KHz\", \"1045 KHz\"], answer: 1, deleted: false, memoryTrick: \"Image = Signal + 2*IF. 1500 + 2(455) = 2410.\", explanation: \"The image frequency formula is fsi = fs + 2*IF.\" },\r\n { id: 55, topic: \"Amplitude Modulation (AM)\", question: \"The function of Compander in Communication system\", options: [\"Equalize SNR for both weak and strong signals\", \"Increase amplification of the signal\", \"Improve multiplexing\", \"Improve A\/D conversion\"], answer: 0, deleted: false, memoryTrick: \"Compand = Compress (strong) + Expand (weak).\", explanation: \"It compresses the dynamic range before transmission to boost weak signals over noise, then expands it at the receiver.\" },\r\n { id: 52, topic: \"Frequency Modulation (FM)\", question: \"The disadvantages of using balanced slope detector for demodulation of FM signal\", options: [\"The detector operates only for small deviation in frequency\", \"Low pass filter of the detector produces distortion in the detection\", \"Both A) and B)\", \"None of the above\"], answer: 2, deleted: false, memoryTrick: \"Slope detectors are non-linear and easily distorted.\", explanation: \"It relies on the non-linear skirts of tuned circuits, limiting linear operation to small deviations.\" },\r\n { id: 56, topic: \"Frequency Modulation (FM)\", question: \"A single tone 5 KHz message signal is sampled with 9 KHz, 7 KHz and 12 KHz. Aliasing effect will be seen in the reconstructed signal when signal is sampled at\", options: [\"7 KHz only\", \"7 KHz and 9 KHz\", \"12 KHz only\", \"7 KHz and 12 KHz\"], answer: 1, deleted: false, memoryTrick: \"Nyquist says sample > 2*MaxFreq. 2*5 = 10. Anything under 10 causes aliasing.\", explanation: \"Since Nyquist rate is 10 KHz, sampling at 7 KHz or 9 KHz violates the theorem and causes aliasing.\" },\r\n { id: 57, topic: \"Frequency Modulation (FM)\", question: \"Indirect method of FM generation<br>i. Does not require the carrier oscillator to respond directly to the modulating signal.<br>ii. Use frequency multiplication.<br>iii. Generate stable FM signal.<br>iv. It involves a crystal oscillator, a phase modulator and frequency multiplier.\", options: [\"Only i\", \"Only i and ii\", \"Only i, ii and iii\", \"All of the above (i, ii, iii and iv)\"], answer: 3, deleted: false, memoryTrick: \"Indirect (Armstrong) uses PM to get FM and needs multipliers.\", explanation: \"The Armstrong method integrates the message, phase modulates a stable crystal carrier, and uses frequency multipliers to achieve the desired deviation.\" },\r\n { id: 58, topic: \"Frequency Modulation (FM)\", question: \"The disadvantages of frequency modulation over amplitude modulation are\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 59, topic: \"Pulse Modulation\", question: \"A PAM signal can be detected using\", options: [\"High pass filter\", \"Low pass filter\", \"Band pass filter\", \"All pass filter\"], answer: 1, deleted: false, memoryTrick: \"Baseband signals hide in low frequencies.\", explanation: \"Pulse Amplitude Modulation (PAM) retains the baseband signal envelope, which can be extracted via a simple low pass filter.\" },\r\n { id: 60, topic: \"Pulse Modulation\", question: \"In Pulse Code Modulation if the number of quantization level is increased from 16 to 256 then the bandwidth requirement will approximately be\", options: [\"2 times\", \"4 times\", \"3 times\", \"16 times\"], answer: 0, deleted: false, memoryTrick: \"Levels go from 2^4 to 2^8. Bits double (4 to 8). BW doubles.\", explanation: \"Bandwidth in PCM is directly proportional to the number of bits (n). Since bits went from 4 to 8, bandwidth doubles.\" },\r\n { id: 61, topic: \"Monochrome Television\", question: \"Which modulation scheme is used in transmitting sound in the monochrome television transmission method?\", options: [\"AM\", \"FM\", \"PM\", \"QAM\"], answer: 1, deleted: false, memoryTrick: \"TV Picture is AM, TV Sound is FM.\", explanation: \"FM is used for sound due to its immunity to noise, which prevents video static from bleeding into the audio.\" },\r\n { id: 62, topic: \"Monochrome Television\", question: \"In a television transmission, which bandwidth-saving method is used in video modulation?\", options: [\"SSB\", \"VSB\", \"DSBSC\", \"DSBFC\"], answer: 1, deleted: false, memoryTrick: \"V = Video = Vestigial (VSB).\", explanation: \"Vestigial Sideband (VSB) transmits one full sideband and a 'vestige' of the other, saving bandwidth while retaining low-frequency video details.\" },\r\n { id: 65, topic: \"Monochrome Television\", question: \"Sound intermediate frequency in monochrome TV receivers in India is\", options: [\"38.9 MHz\", \"38.9 KHz\", \"33.4 MHz\", \"33.4 KHz\"], answer: 2, deleted: false, memoryTrick: \"Picture IF is 38.9, Sound IF is 33.4 (Difference is 5.5 MHz).\", explanation: \"In the CCIR system used in India, Picture IF is 38.9 MHz and Sound IF is 33.4 MHz.\" },\r\n { id: 63, topic: \"Colour Television\", question: \"Colour-killer, kills the colour when\", options: [\"Colour burst signal is present\", \"Colour burst signal is absent\", \"Colour is excessive\", \"Monochrome receiver is used\"], answer: 1, deleted: false, memoryTrick: \"No burst = no color signal = kill the color noise.\", explanation: \"The color killer circuit disables the chrominance amplifier during a monochrome broadcast to prevent colored 'confetti' noise on screen.\" },\r\n { id: 64, topic: \"Colour Television\", question: \"Which stages of the colour TV receiver controls contrast and brightness?\", options: [\"Video detector\", \"Comb filter\", \"Colour killer circuit\", \"Luminance amplifier\"], answer: 3, deleted: false, memoryTrick: \"Luminance = Luma = Y = Brightness.\", explanation: \"The luminance (Y) signal contains the black-and-white picture information, governing overall brightness and contrast.\" },\r\n { id: 66, topic: \"Radar Systems\", question: \"Blind speed problem in radar is avoided using\", options: [\"Use of mono pulse\", \"Increase the gain\", \"Vary the pulse repetition frequency\", \"Change the Doppler frequency\"], answer: 2, deleted: false, memoryTrick: \"Vary the PRF to 'stagger' the blindness.\", explanation: \"Blind speeds occur when the Doppler shift equals a multiple of the PRF. Using staggered (varying) PRF shifts the blind speeds.\" },\r\n { id: 67, topic: \"Radar Systems\", question: \"If the peak power of the radar is increased 16 times and other parameters are constant, the range of the radar is\", options: [\"Increased by 2 times\", \"Increased by 4 times\", \"Increased by 8 times\", \"Increased by 16 times\"], answer: 0, deleted: false, memoryTrick: \"Range is proportional to 4th root of Power. 16^(1\/4) = 2.\", explanation: \"According to the Radar Equation, Rmax depends on Pt^(1\/4). 16^(1\/4) = 2.\" },\r\n { id: 68, topic: \"Radar Systems\", question: \"Plan Position Indicator (PPI) displays\", options: [\"Amplitude of received echoes\", \"Map of the target area\", \"The target range, but not position\", \"The target position, but not range\"], answer: 1, deleted: false, memoryTrick: \"PPI is the classic sweeping circular radar screen you see in movies.\", explanation: \"PPI uses polar coordinates to display range and azimuth, creating a map-like 2D view of the target area.\" },\r\n { id: 69, topic: \"Optical Fiber Communication\", question: \"Dispersion is\", options: [\"Bending of light as it passes through an opening in an obstacle\", \"Light strikes a surface and is converted into heat\", \"Separating light into each of its component frequencies\", \"Light strike a substance which emits light at the same wavelength\"], answer: 2, deleted: false, memoryTrick: \"Dispersion disperses the colors (like a prism).\", explanation: \"Chromatic dispersion causes different wavelengths of a light pulse to travel at different speeds, broadening the pulse.\" },\r\n { id: 70, topic: \"Optical Fiber Communication\", question: \"Which optical detector provides internal amplification using impact ionisation?\", options: [\"Photo transistor\", \"PIN diode\", \"Avalanche photo diode\", \"Photo detector\"], answer: 2, deleted: false, memoryTrick: \"Avalanche = cascade of electrons (impact ionization).\", explanation: \"Avalanche Photodiodes (APDs) use high reverse bias to accelerate electrons, causing secondary emissions (impact ionization) and internal gain.\" },\r\n { id: 71, topic: \"ISDN\", question: \"In an ISDN Basic Rate Interface (BRI), signalling information between the user and network is managed through\", options: [\"B-channel\", \"D-channel\", \"Both B-channels alternately\", \"External control line\"], answer: 1, deleted: false, memoryTrick: \"B for Bearer (Data), D for Delta\/Data-link (Signaling).\", explanation: \"The 16 kbps D-channel is dedicated to out-of-band signaling and control for the two B-channels.\" },\r\n { id: 72, topic: \"Facsimile\", question: \"The 'Index of Cooperation (IOC)' in facsimile transmission relates to\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 73, topic: \"Facsimile\", question: \"Which recording method in a facsimile receiver gives high-quality reproduction and is often used in commercial fax machines?\", options: [\"Option A\", \"Option B\", \"Option C\", \"Option D\"], answer: -1, deleted: true, memoryTrick: \"\", explanation: \"Cancelled Question.\" },\r\n { id: 74, topic: \"Digital Modulation\", question: \"A system transmits at a bit rate of 4 Mbps using raised cosine filtering with a roll-off factor of 0.25. The required minimum transmission bandwidth is approximately\", options: [\"2 MHz\", \"2.5 MHz\", \"3 MHz\", \"4 MHz\"], answer: 1, deleted: false, memoryTrick: \"BW = (Rb\/2) * (1 + alpha). 2 * 1.25 = 2.5.\", explanation: \"For baseband transmission, minimum Nyquist BW is Rb\/2. With roll-off, BW = (4\/2) * (1 + 0.25) = 2.5 MHz.\" },\r\n { id: 75, topic: \"Digital Modulation\", question: \"If the number of symbols transmitted per second in a digital communication system is increased while each symbol still represents the same number of bits, then\", options: [\"Bit rate remains constant but baud rate increases\", \"Both bit rate and baud rate increases\", \"Bit rate decreases but baud rate increases\", \"Bit rate increases but baud rate remains constant\"], answer: 1, deleted: false, memoryTrick: \"Baud rate = Symbols\/sec. Bit rate = Symbols\/sec * bits\/symbol.\", explanation: \"Since baud rate increases and bits\/symbol is constant, their product (bit rate) also increases.\" },\r\n { id: 76, topic: \"Digital Modulation\", question: \"For the Assertion (A) and Reason (R) given below, choose the correct alternative:<br>Assertion (A): Equalizers are used in digital systems to reduce Inter-Symbol Interference (ISI).<br>Reason (R): Equalizers modify the frequency response of the channel.\", options: [\"Both (A) and (R) are true and (R) correctly explains (A)\", \"Both (A) and (R) are true, but (R) does not explain (A)\", \"(A) is true, (R) is false\", \"Both (A) and (R) are false\"], answer: 0, deleted: false, memoryTrick: \"Equalize = flatten out the channel's flaws.\", explanation: \"Channel distortion causes ISI. Equalizers apply an inverse filter response to flatten the channel and cancel the ISI.\" },\r\n { id: 79, topic: \"Digital Modulation\", question: \"In an ASK demodulator, the envelope detector primarily\", options: [\"Recovers the carrier phase for synchronization\", \"Converts amplitude fluctuations into corresponding baseband signal\", \"Maintains constant envelope for improved SNR\", \"Reduces amplitude distortion caused by channel noise\"], answer: 1, deleted: false, memoryTrick: \"ASK is digital AM. Envelope detector grabs the amplitude.\", explanation: \"An envelope detector traces the amplitude outline of the ASK signal to recover the original baseband digital pulses.\" },\r\n { id: 80, topic: \"Digital Modulation\", question: \"Which of the following correctly describes a synchronous modem?\", options: [\"Requires separate clock line\", \"Transfers data in asynchronous blocks\", \"Does not use start\/stop bits\", \"Both A) and C)\"], answer: 3, deleted: false, memoryTrick: \"Synchronous = Synced by a clock, no need for start\/stop bumpers.\", explanation: \"Synchronous transmission relies on a shared clock signal to frame data, eliminating the overhead of start and stop bits used in asynchronous data.\" },\r\n { id: 77, topic: \"Error Detection and Coding\", question: \"Match the following digital codes with their descriptions:<br>a. Baudot code b. ASCII c. EBCDIC d. Hamming code<br>1. Text 7-bit code 2. Error correction code 3. Teleprinter 5-bit code 4. IBM 8-bit code\", options: [\"a \u2013 3, b \u2013 1, c \u2013 4, d \u2013 2\", \"a \u2013 1, b \u2013 4, c \u2013 3, d \u2013 2\", \"a \u2013 4, b \u2013 1, c \u2013 3, d \u2013 2\", \"a \u2013 3, b \u2013 2, c \u2013 1, d \u2013 4\"], answer: 0, deleted: false, memoryTrick: \"ASCII = 7-bit text. Hamming = Error.\", explanation: \"Baudot is an early 5-bit teleprinter code. ASCII is standard 7-bit. EBCDIC is IBM's 8-bit. Hamming corrects errors.\" },\r\n { id: 78, topic: \"Error Detection and Coding\", question: \"The minimum Hamming distance required to correct two errors and detect three is\", options: [\"3\", \"4\", \"5\", \"6\"], answer: 2, deleted: false, memoryTrick: \"dmin >= t + e + 1 (where e > t). dmin >= 2 + 3 + 1 = 6? Wait, dmin >= 2t+1 for correct 2 (dmin=5).\", explanation: \"To correct 't' errors: dmin >= 2t+1. So 2(2)+1 = 5. To detect 'e' errors: dmin >= e+1. 3+1 = 4. The larger requirement is 5.\" },\r\n { id: 81, topic: \"Satellite Communication\", question: \"Geostationary satellites are located approximately\", options: [\"3600 kilometers above the earth\", \"36000 kilometers above the earth\", \"600 kilometers above the earth\", \"400 kilometers above the earth\"], answer: 1, deleted: false, memoryTrick: \"GEO = 36,000 km.\", explanation: \"At ~35,786 km above the equator, the satellite's orbital period matches Earth's rotation (24 hours).\" },\r\n { id: 82, topic: \"Satellite Communication\", question: \"Kepler's third law states that\", options: [\"The orbit of a planet is an ellipse\", \"A line segment joining a planet and the sun sweeps out equal areas\", \"The cube of a planet's orbital period is proportional to the square of the length\", \"The square of a planet's orbital period is proportional to the cube of the length of the semi major axis\"], answer: 3, deleted: false, memoryTrick: \"T^2 is proportional to a^3 (Squares are Cubes).\", explanation: \"The square of the orbital period (T) is directly proportional to the cube of the semi-major axis (a).\" },\r\n { id: 83, topic: \"Satellite Communication\", question: \"The orbit which is below 1000 kilometer distance from the sea level is called\", options: [\"Medium Earth Orbit (MEO)\", \"High Earth Orbit (HEO)\", \"Low Earth Orbit (LEO)\", \"Geosynchronous Earth Orbit (GEO)\"], answer: 2, deleted: false, memoryTrick: \"Below 1000 = Low.\", explanation: \"Low Earth Orbit (LEO) generally ranges from 160 km to 2,000 km.\" },\r\n { id: 84, topic: \"Satellite Communication\", question: \"Closest distance of the satellite orbit to earth is\", options: [\"Perigee\", \"Apogee\", \"Skip distance\", \"Focal length\"], answer: 0, deleted: false, memoryTrick: \"Perigee = Perilously close. Apogee = Away.\", explanation: \"In an elliptical orbit, perigee is the point of closest approach to the central body.\" },\r\n { id: 85, topic: \"Satellite Communication\", question: \"Active satellites have\", options: [\"Power source\", \"Transponders\", \"Signal Processing Unit\", \"All of the above\"], answer: 3, deleted: false, memoryTrick: \"Active means it does work (amplifies\/processes), so it needs all these.\", explanation: \"Unlike passive reflectors, active satellites receive, amplify, process, and re-transmit signals using onboard power and transponders.\" },\r\n { id: 86, topic: \"Satellite Communication\", question: \"The sub system in satellite communication responsible for collecting data from on-board sensors to monitor the health and performance of a satellite is\", options: [\"Tracking sub system\", \"Command sub system\", \"Telemetry sub system\", \"Earth station\"], answer: 2, deleted: false, memoryTrick: \"Tele-metry = Measure from far away.\", explanation: \"Telemetry involves gathering sensor data (temperature, voltage, pressure) and transmitting it to Earth.\" },\r\n { id: 87, topic: \"Satellite Communication\", question: \"INTELSAT stands for\", options: [\"International Telecommunication Satellite\", \"Indian Telecommunication Satellite\", \"Inter Telecommunication Satellite\", \"None of the above\"], answer: 0, deleted: false, memoryTrick: \"INTEL = INTernational + TELecommunications.\", explanation: \"Formed in 1964 as the International Telecommunications Satellite Organization.\" },\r\n { id: 88, topic: \"Satellite Communication\", question: \"Geographical representation of satellite antenna radiation pattern is called\", options: [\"Spot\", \"Foot print\", \"Beam\", \"Region\"], answer: 1, deleted: false, memoryTrick: \"The footprint is where the satellite 'steps' its signal on Earth.\", explanation: \"A footprint is a map showing the contour lines of Equal Effective Isotropic Radiated Power (EIRP) covering the ground.\" },\r\n { id: 89, topic: \"Satellite Communication\", question: \"Which of the following is a satellite earth station antenna?\", options: [\"Helical antenna\", \"Toroidal antenna\", \"Yagi-Uda antenna\", \"Cassagrain antenna\"], answer: 3, deleted: false, memoryTrick: \"Cassagrain has a sub-reflector to easily mount heavy LNBs behind the dish.\", explanation: \"Cassegrain reflector antennas are widely used in earth stations because feed electronics can be mounted behind the main dish.\" },\r\n { id: 90, topic: \"Satellite Communication\", question: \"The unit which detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency is\", options: [\"Satellite receiver\", \"LNA\", \"Horn Antenna\", \"Dish\"], answer: 1, deleted: false, memoryTrick: \"Low Noise Amplifier\/Block (LNB\/LNA).\", explanation: \"The Low Noise Amplifier (often part of an LNB) grabs the weak microwave signal, amplifies it with minimal noise, and downconverts it.\" },\r\n { id: 91, topic: \"Cellular Concepts\", question: \"A simplified cellular telephone system primarily aims to\", options: [\"Increase base station size\", \"Enable frequency reuse across cells\", \"Eliminate all interference\", \"Use only wired connections\"], answer: 1, deleted: false, memoryTrick: \"Cellular means dividing areas into cells to reuse the same frequencies safely.\", explanation: \"Frequency reuse is the core concept of cellular networks, allowing limited spectrum to support unlimited subscribers.\" },\r\n { id: 92, topic: \"Cellular Concepts\", question: \"CDMA allows multiple users on the same frequency using\", options: [\"Unique codes\", \"Time slots\", \"Sectors\", \"Guard bands\"], answer: 0, deleted: false, memoryTrick: \"Code Division = Unique Codes.\", explanation: \"Code Division Multiple Access assigns unique spreading codes to users, allowing them to share the exact same frequency band simultaneously.\" },\r\n { id: 93, topic: \"Cellular Concepts\", question: \"Roaming in cellular systems allows\", options: [\"Fixed location calls only\", \"Users to move between different networks\", \"No handoff\", \"Satellite-only access\"], answer: 1, deleted: false, memoryTrick: \"Roaming = wandering into a different provider's territory.\", explanation: \"Roaming enables a mobile user to automatically connect to a visiting network when outside their home network's coverage.\" },\r\n { id: 94, topic: \"Cellular Concepts\", question: \"Improving coverage and capacity in cellular systems includes techniques like\", options: [\"Reducing frequency reuse\", \"Increasing tower height\", \"Cell splitting and sectoring\", \"Eliminating handoff\"], answer: 2, deleted: false, memoryTrick: \"Splitting makes smaller cells (more capacity). Sectoring uses directional antennas.\", explanation: \"Cell splitting increases channels per unit area. Sectoring reduces co-channel interference, allowing closer reuse.\" },\r\n { id: 95, topic: \"GSM\", question: \"In GSM, radio subsystem uses\", options: [\"Quadrature Phase Shift Keying (QPSK)\", \"Amplitude Shift Keying (ASK)\", \"CDMA\", \"Gaussian Minimum Shift Keying (GMSK)\"], answer: 3, deleted: false, memoryTrick: \"GSM uses GMSK.\", explanation: \"GMSK provides constant envelope modulation, which allows the use of highly efficient non-linear amplifiers in mobile devices.\" },\r\n { id: 96, topic: \"GSM\", question: \"For a cellular system with cluster size N = 7, if the total available channels are 395 and each cell is allocated the same number of channels, how many channels are available per cell?\", options: [\"50\", \"56\", \"65\", \"70\"], answer: 1, deleted: false, memoryTrick: \"395 \/ 7 = 56.42. Since you can't have half a channel, it's 56.\", explanation: \"Total channels \/ N. 395 \/ 7 = 56 channels per cell, leaving 3 channels unused.\" },\r\n { id: 97, topic: \"GSM\", question: \"The full form of GSM in the cellular service is\", options: [\"Global System for Mobile Communications\", \"General Mobile System\", \"Global Mobile Satellite\", \"None of the above\"], answer: 0, deleted: false, memoryTrick: \"Global System for Mobile.\", explanation: \"Originally Groupe Sp\u00e9cial Mobile, it was renamed Global System for Mobile Communications as it became an international standard.\" },\r\n { id: 98, topic: \"GSM\", question: \"In a hexagonal cellular system with a frequency reuse cluster size of 7, what is the co-channel reuse ratio (Q)?\", options: [\"3.65\", \"4.0\", \"4.58\", \"5.34\"], answer: 2, deleted: false, memoryTrick: \"Q = \u221a(3N). \u221a(3*7) = \u221a21 \u2248 4.58.\", explanation: \"The reuse ratio Q determines the spatial separation between co-channel cells relative to cell radius.\" },\r\n { id: 99, topic: \"GSM\", question: \"Which interference type is mitigated by proper channel assignment?\", options: [\"Co-Channel Interference\", \"Adjacent Channel Interference\", \"Both A) and B)\", \"Neither A) nor B)\"], answer: 2, deleted: false, memoryTrick: \"Assignment spacing fixes adjacent. Assignment location fixes co-channel.\", explanation: \"Geographic separation fixes co-channel interference, while frequency gaps (guard bands\/assignment) fix adjacent channel interference.\" },\r\n { id: 100, topic: \"GSM\", question: \"FDMA stands for\", options: [\"Frequency Division Multiple Access\", \"Frequency Domain Multiple Access\", \"Full Division Multiple Access\", \"Fixed Division Multiple Access\"], answer: 0, deleted: false, memoryTrick: \"Divide by Frequency.\", explanation: \"FDMA gives each user a discrete frequency slice of the spectrum.\" }\r\n ];\r\n\r\n var currentMode = 'learning';\r\n var currentFilter = 'All';\r\n var userAnswers = {};\r\n var individualAnswersVisible = {};\r\n var allAnswersRevealed = false;\r\n var testSubmitted = false;\r\n var showingOnlyWrong = false;\r\n var userVotes = {};\r\n var wrongQuestionIds = []; \r\n \r\n var isPremium = false;\r\n\r\n window.onload = function() {\r\n extractTopicsAndRenderFilters();\r\n renderQuestions();\r\n };\r\n\r\n function renderQuestions() {\r\n var container = document.getElementById('quiz-container');\r\n var htmlString = \"\";\r\n var visibleCount = 0;\r\n var currentTopicTracker = \"\";\r\n\r\n for (var i = 0; i < questionsData.length; i++) {\r\n var q = questionsData[i];\r\n\r\n if (currentFilter !== 'All' && q.topic !== currentFilter) {\r\n continue;\r\n }\r\n\r\n if (showingOnlyWrong) {\r\n if (wrongQuestionIds.indexOf(q.id) === -1) {\r\n continue; \r\n }\r\n }\r\n\r\n if (currentMode === 'attempt' && !isPremium && visibleCount >= 4) {\r\n htmlString += \"<div class='card paywall-card'>\";\r\n htmlString += \"<h2 style='color:var(--primary-color); margin-bottom:10px;'>\ud83d\udd12 Unlock Full Test<\/h2>\";\r\n htmlString += \"<p>You have completed the free preview of Attempt Mode.<\/p>\";\r\n htmlString += \"<p>Upgrade your account to unlock all 100 questions, see your final score, detailed reports, and access 'Reattempt Wrong Questions' features.<\/p>\";\r\n htmlString += \"<a href='YOUR_PAYMENT_LINK_HERE' class='paywall-btn'>Upgrade Now to Unlock All<\/a>\";\r\n htmlString += \"<\/div>\";\r\n break;\r\n }\r\n\r\n visibleCount++;\r\n\r\n if (q.topic !== currentTopicTracker) {\r\n htmlString += \"<h2 class='section-heading'>\" + q.topic + \"<\/h2>\";\r\n currentTopicTracker = q.topic;\r\n }\r\n\r\n htmlString += \"<div class='card' id='card-\" + q.id + \"'>\";\r\n htmlString += \"<div class='q-text'><strong>Q\" + visibleCount + \".<\/strong> \" + q.question + \"<\/div>\";\r\n \r\n htmlString += \"<div class='options-grid'>\";\r\n for (var j = 0; j < q.options.length; j++) {\r\n var optionLetter = String.fromCharCode(65 + j);\r\n var optionClass = \"option-item\";\r\n \r\n if (userAnswers[q.id] === j) optionClass += \" selected\";\r\n \r\n if (currentMode === 'attempt' && testSubmitted && !q.deleted) {\r\n if (q.answer === j) {\r\n optionClass += \" correct-opt\";\r\n } else if (userAnswers[q.id] === j && q.answer !== j) {\r\n optionClass += \" wrong-opt\";\r\n }\r\n }\r\n\r\n var clickAction = \"\";\r\n if (currentMode === 'attempt' && !testSubmitted) {\r\n clickAction = \"onclick='selectOption(\" + q.id + \", \" + j + \")'\";\r\n }\r\n\r\n htmlString += \"<div class='\" + optionClass + \"' \" + clickAction + \">\";\r\n htmlString += \"<strong>\" + optionLetter + \")<\/strong> \" + q.options[j];\r\n htmlString += \"<\/div>\";\r\n }\r\n htmlString += \"<\/div>\";\r\n\r\n if (currentMode === 'learning') {\r\n var btnText = individualAnswersVisible[q.id] ? \"Hide Answer\" : \"Show Answer\";\r\n htmlString += \"<button onclick='toggleSingleAnswer(\" + q.id + \")'>\" + btnText + \"<\/button>\";\r\n }\r\n\r\n var showAnsSection = false;\r\n if (currentMode === 'learning' && (allAnswersRevealed || individualAnswersVisible[q.id])) {\r\n showAnsSection = true;\r\n } else if (currentMode === 'attempt' && testSubmitted) {\r\n showAnsSection = true;\r\n }\r\n\r\n var ansDisplayStyle = showAnsSection ? \"display:block;\" : \"display:none;\";\r\n htmlString += \"<div class='answer-section' id='ans-section-\" + q.id + \"' style='\" + ansDisplayStyle + \"'>\";\r\n \r\n htmlString += \"<div class='ans-reveal'>\";\r\n if (q.deleted) {\r\n htmlString += \"<span class='deleted-text'>Deleted \u2014 no official answer<\/span>\";\r\n } else {\r\n var correctLetter = String.fromCharCode(65 + q.answer);\r\n htmlString += \"<span class='correct-text'>Correct Answer: \" + correctLetter + \") \" + q.options[q.answer] + \" \u2705<\/span>\";\r\n }\r\n htmlString += \"<\/div>\";\r\n\r\n if (!q.deleted && currentMode === 'attempt' && testSubmitted) {\r\n htmlString += \"<div class='disclaimer'><i>This Memory Trick is AI generated. Verify with standard sources.<\/i><\/div>\";\r\n htmlString += \"<div class='memory-trick'>\ud83e\udde0 <strong>Memory Trick:<\/strong> \" + q.memoryTrick + \"<\/div>\";\r\n htmlString += \"<div class='disclaimer'><i>This explanation all are user generated. Verify with standard sources.<\/i><\/div>\";\r\n htmlString += \"<div class='explanation'>\ud83d\udcd6 <strong>Explanation:<\/strong> \" + q.explanation + \"<\/div>\";\r\n\r\n var upVotes = userVotes[q.id] === 'up' ? 1 : 0;\r\n var downVotes = userVotes[q.id] === 'down' ? 1 : 0;\r\n \r\n htmlString += \"<div class='interaction-bar'>\";\r\n htmlString += \"<span>Helpful? \";\r\n htmlString += \"<button class='vote-btn' onclick='castVote(\" + q.id + \", \\\"up\\\")'>\ud83d\udc4d \" + upVotes + \"<\/button> \";\r\n htmlString += \"<button class='vote-btn' onclick='castVote(\" + q.id + \", \\\"down\\\")'>\ud83d\udc4e \" + downVotes + \"<\/button>\";\r\n htmlString += \"<\/span>\";\r\n htmlString += \"<span style='margin-left:15px;'>Difficulty: <select><option>Easy<\/option><option>Medium<\/option><option>Hard<\/option><\/select><\/span>\";\r\n htmlString += \"<button class='report-btn' onclick='alert(\\\"Thank you! Error reported to admin.\\\")'>Report Error<\/button>\";\r\n htmlString += \"<\/div>\";\r\n }\r\n\r\n htmlString += \"<\/div>\";\r\n htmlString += \"<\/div>\";\r\n }\r\n\r\n container.innerHTML = htmlString;\r\n document.getElementById('question-counter').innerText = \"Showing \" + visibleCount + \" questions\";\r\n }\r\n\r\n function setMode(mode) {\r\n currentMode = mode;\r\n testSubmitted = false;\r\n showingOnlyWrong = false;\r\n wrongQuestionIds = []; \r\n userAnswers = {};\r\n individualAnswersVisible = {};\r\n allAnswersRevealed = false;\r\n\r\n document.getElementById('btn-mode-learning').className = mode === 'learning' ? 'active-btn' : '';\r\n document.getElementById('btn-mode-attempt').className = mode === 'attempt' ? 'active-btn' : '';\r\n \r\n document.getElementById('btn-toggle-all').style.display = mode === 'learning' ? 'inline-block' : 'none';\r\n document.getElementById('submit-fab').style.display = mode === 'attempt' ? 'block' : 'none';\r\n document.getElementById('results-panel').style.display = 'none';\r\n document.getElementById('score-display').style.display = 'none';\r\n\r\n document.getElementById('filter-buttons').style.display = mode === 'learning' ? 'flex' : 'none';\r\n\r\n if (mode === 'attempt') {\r\n currentFilter = 'All';\r\n var selectMenu = document.getElementById('topic-select');\r\n if (selectMenu) {\r\n selectMenu.value = 'All';\r\n }\r\n }\r\n\r\n renderQuestions();\r\n }\r\n\r\n function extractTopicsAndRenderFilters() {\r\n var topics = [\"All\"];\r\n for (var i = 0; i < questionsData.length; i++) {\r\n if (topics.indexOf(questionsData[i].topic) === -1) {\r\n topics.push(questionsData[i].topic);\r\n }\r\n }\r\n\r\n var filterContainer = document.getElementById('filter-buttons');\r\n var html = \"<strong style='margin-right: 10px;'>Subject:<\/strong> <select id='topic-select' onchange='setFilter(this.value)'>\";\r\n for (var j = 0; j < topics.length; j++) {\r\n var selected = topics[j] === currentFilter ? \"selected\" : \"\";\r\n html += \"<option value='\" + topics[j] + \"' \" + selected + \">\" + topics[j] + \"<\/option>\";\r\n }\r\n html += \"<\/select>\";\r\n filterContainer.innerHTML = html;\r\n }\r\n\r\n function setFilter(topicName) {\r\n currentFilter = topicName;\r\n extractTopicsAndRenderFilters();\r\n renderQuestions();\r\n }\r\n\r\n function selectOption(questionId, optionIndex) {\r\n if (currentMode !== 'attempt' || testSubmitted) return;\r\n userAnswers[questionId] = optionIndex;\r\n renderQuestions();\r\n }\r\n\r\n function submitTest() {\r\n var score = 0;\r\n var totalValid = 0;\r\n var evaluatedCount = 0;\r\n wrongQuestionIds = []; \r\n\r\n for (var i = 0; i < questionsData.length; i++) {\r\n var q = questionsData[i];\r\n \r\n if (currentFilter !== 'All' && q.topic !== currentFilter) continue;\r\n if (showingOnlyWrong && (q.deleted || userAnswers[q.id] === q.answer)) continue;\r\n\r\n if (currentMode === 'attempt' && !isPremium && evaluatedCount >= 4) {\r\n break; \r\n }\r\n evaluatedCount++;\r\n\r\n if (!q.deleted) {\r\n totalValid++;\r\n if (userAnswers[q.id] === q.answer) {\r\n score++;\r\n } else {\r\n wrongQuestionIds.push(q.id);\r\n }\r\n }\r\n }\r\n\r\n testSubmitted = true;\r\n document.getElementById('submit-fab').style.display = 'none';\r\n \r\n document.getElementById('results-panel').style.display = 'block';\r\n document.getElementById('final-score-text').innerText = \"Score: \" + score + \" \/ \" + totalValid;\r\n \r\n var scoreDisp = document.getElementById('score-display');\r\n scoreDisp.style.display = 'inline-block';\r\n scoreDisp.innerText = \"Current Score: \" + score + \"\/\" + totalValid;\r\n\r\n window.scrollTo({ top: 0, behavior: 'smooth' });\r\n renderQuestions();\r\n }\r\n\r\n function reattemptWrong() {\r\n showingOnlyWrong = true;\r\n testSubmitted = false;\r\n \r\n for (var i = 0; i < wrongQuestionIds.length; i++) {\r\n delete userAnswers[wrongQuestionIds[i]];\r\n }\r\n\r\n document.getElementById('results-panel').style.display = 'none';\r\n document.getElementById('score-display').style.display = 'none';\r\n document.getElementById('submit-fab').style.display = 'block';\r\n \r\n renderQuestions();\r\n }\r\n\r\n function toggleSingleAnswer(questionId) {\r\n if (individualAnswersVisible[questionId]) {\r\n individualAnswersVisible[questionId] = false;\r\n } else {\r\n individualAnswersVisible[questionId] = true;\r\n }\r\n renderQuestions();\r\n }\r\n\r\n function toggleAllAnswers() {\r\n allAnswersRevealed = !allAnswersRevealed;\r\n var btn = document.getElementById('btn-toggle-all');\r\n btn.innerText = allAnswersRevealed ? \"Hide All Answers\" : \"Reveal All Answers\";\r\n individualAnswersVisible = {}; \r\n renderQuestions();\r\n }\r\n\r\n function castVote(questionId, type) {\r\n if (userVotes[questionId] === type) {\r\n delete userVotes[questionId];\r\n } else {\r\n userVotes[questionId] = type;\r\n }\r\n renderQuestions();\r\n }\r\n<\/script>\r\n<\/body>\r\n<\/html>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"pmpro_default_level":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-7","post","type-post","status-publish","format-standard","hentry","category-uncategorized","pmpro-has-access"],"_links":{"self":[{"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/posts\/7","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7"}],"version-history":[{"count":2,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/posts\/7\/revisions"}],"predecessor-version":[{"id":13,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=\/wp\/v2\/posts\/7\/revisions\/13"}],"wp:attachment":[{"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/keralatechnicalpsc.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}