LREN ‘Q’ Suitability Exam PDF

RESTRICTED LREN ‘Q’ SUITABILITY Digital Electronics-l 1. The binary number of decimal number 32 is ___ a. (100000)2 b. (101100)2 c. (111111)2 d. (010101)2 Ans: a. (100...

RESTRICTED LREN ‘Q’ SUITABILITY Digital Electronics-l 1. The binary number of decimal number 32 is ___ a. (100000)2 b. (101100)2 c. (111111)2 d. (010101)2 Ans: a. (100000)2 2. ___ and ____ gates are universal gates? a. NAND and AND b. NAND and NOR c. NAND and OR d. None of the above Ans b. NAND and NOR 3. Which gate is used to made IC decoders? a. NAND b. NOR c. AND d. None of the above Ans: a. NAND 4. Who invented Gray code? a. Frank Gray b. Dom Hofmann c. Aryabhatta d. None of the above Ans: a. Frank Gray 5. How many OR gates are used to made encoders a. One b. Two c. Three d. Four Ans: b. Two 6. In which gate the output is high when any one or all inputs are high? a. AND b. NAND c. OR d. NOR Ans: c. OR 7. If the current is same for the different time then it is _____ a. Direct current b. Discrete current c. Alternative current d. None of the above Ans: a. Direct current 8. The transducers converts ___ a. Non-electrical signals into electrical signals b. Electrical signals into non-electrical signals c. Electrical signals into electromagnetic waves d. None of the above Ans: a. Non-electrical signals into electrical signals 9. Choose the odd one out a. Watch b. Calculator c. Computer d. Coal Ans: d. Coal 10. ______ is used in communication process to minimize the effect of noise a. Digital signal b. Analog signal c. Electrical signal 1 RESTRICTED  RESTRICTED d. None of the above Ans: a. Digital signal 11. What are the advantages of the digital systems? a. High-efficiency b. Uses less bandwidth c. Encryption d. All of the above Ans: d. All of the above 12. The reverse transducer converts _____ a. Non-electrical signals into electrical signals b. Electrical signals into non-electrical signals c. Electrical signals into electromagnetic waves d. None of the above Ans: b. Electrical signals into non-electrical signals 13. How many possibilities do two switches have? a. One b. Two c. Three d. Four Ans: d. Four 14. How many possibilities does two-bit number have? a. One b. Two c. Three d. Four Ans: d. Four 15. The number of switches is equal to the ___ a. Number of digits b. Number of bytes c. Number of bits d. None of the above Ans: c. Number of bits 16). The 8 bits is equal to the ____ bytes a. One-byte b. Two-bytes c. Three-bytes d. None of the above Ans: a. One-byte 17. The Boolean algebra is given by ___ a. Ronald J Tocci b. Pascal c. George Boole d. None of the above Ans: c. George Boole 18. What is the standard form of PIPO? a. Parallel Input Parallel Output b. Parallel Output Parallel Input c. Positive Input Positive Output d. None of the above Ans: a. Parallel Input Parallel Output 19. How many types of number systems are there? a. Two b. Three c. Four d. Five Ans: d. Five 2 RESTRICTED  RESTRICTED 20. What is the base of octal? a. 2 b. 8 c. 12 d. 10 Ans: b. 8 21. What are the examples of weighted number systems and code? a. Decimal b. Binary c. Octal d. All of the above Ans: d. All of the above 22. What are the examples of un-weighted number systems and code? a. Gray code b. Excess-3 code c. Both a and b d. None of the above Ans: c. Both a and b 23. All real-life signals are ____ in nature a. Digital b. Analog c. Discrete d. None of the above Ans: b. Analog 24. How many roles does Boolean Algebra have __ a. Two b. Three c. Four d. Five Ans: d. Five 25. What are the conditions of the redundancy theorem? a. Each variable is repeated twice b. One variable is complimented c. Take the complimented variable d. All of the above Ans: d. All of the above 26. What are the basic gates? a. AND b. NOT c. OR d. All of the above Ans: d. All of the above 27. In positive logic ____ a. Higher voltage corresponds to logic 1 b. Lower voltage corresponds to logic 0 c. Both a and b d. None of the above Ans: c. Both a and b 28. What is the base of the hexadecimal number system? a. 2 b. 8 c. 10 d. 16 Ans: d. 16 29. Hamming code is invented by ____ a. 1-bit b. 2-bits c. 3-bits d. 4-bits Ans: d. 4-bits 30. How many bits does one nibble have ___ 3 RESTRICTED  RESTRICTED a. 1-bit b. 2-bits c. 3-bits d. 4-bits Ans: d. 4-bits 31. The different names of gray code _____ a. Cyclic code b. Unit distance code c. Minimum error code d. All of the above Ans: d. All of the above 32. The code is ____ a. Group of bits b. Group of bytes c. Group of digits d. Group of symbols Ans: d. Group of symbols 33. The reflective code is also called as ___ a. Diminished complement code b. Radix complement code c. Self-complement code d. None of the above Ans: c. Self-complement code 34. The r’s complement is also called as ____ a. Radix complement b. Diminished complement c. Diminished radix complement d. None of the above Ans: a. Radix complement 35. The (r-1)’s complement is also called as ____ a. Radix complement b. Diminished complement c. Diminished radix complement d. None of the above Ans: c. Diminished radix complement 36. ____ gate is a universal gate a. NOT b. NOR c. AND d. Exclusive OR Ans: a. NOT 37. The Gray code is also called as ____ a. Complement code b. Binary code c. Reflected code d. Reflected binary code Ans: d. Reflected binary code 38. The parity is used to ____ a. Increase the switching operation b. Reduce switching operation c. Detect errors d. None of the above Ans: c. Detect errors 4 RESTRICTED  RESTRICTED 39. The logic gates are divided into __ groups a. One b. Two c. Three d. Four Ans: d. Four 40. What are the arithmetic gate? a. NAND and NOR b. AND and NAND c. X-OR and X-NOR d. None of the above Ans: c. X-OR and X-NOR 41. When all the inputs are high the output is also high in ___ gate a. AND b. NAND c. NOR d. None of the above Ans: a. AND 42. Gray code is used in ____ communication a. Analog communication b. Digital communication c. Both analog and digital d. None of the above Ans: b. Digital communication 43. The group of 1’s is also called as _____ a. Implicants b. Prime implicants c. Essential prime implicants d. None of the above Ans: a. Implicants 44. In which circuit the output is dependent only on the present input ____ a. Combinational circuit b. Sequential circuit c. Both a and b d. None of the above Ans: a. Combinational circuit 45. How many types of codes are there ___ a. One b. Two c. Three d. Six Ans: d. Six 46. How many bits does one byte have? a. 4 bits b. 8 bits c. 16 bits d. 32 bits Ans: b. 8 bits 47. How many bits does one word have? a. 4 bits b. 8 bits c. 16 bits d. 32 bits Ans: c. 16 bits 5 RESTRICTED  RESTRICTED 48. In ____ implicants there is at least a single 1 which cannot be combined in any other way a. Prime implicants b. Essential implicants c. Essential prime implicants d. None of the above Ans: c. Essential prime implicants 49. In which circuit the output is dependent on the present input as well as previous output or outputs a. Combinational circuit b. Sequential circuit c. Both a and b d. None of the above Ans: b. Sequential circuit 50. In negative logic ____ a. Higher voltage corresponds to logic 0 b. Lower voltage corresponds to logic 1 c. Both a and b d. None of the above Ans: c. Both a and b 51. In digital signals we descritise _____ a. Time b. Magnitude c. Both time and magnitude d. None of the above Ans: c. Both time and magnitude 52. ____ is the signal which is defined for the discrete interval of time a. Analog signal b. Digital signal c. Discrete time signal d. None of the above Ans: c. Discrete time signal 53. What is the base of hexadecimal ___ a. 16 b. 8 c. 32 d. None of the above Ans: a. 16 54. What is the base of duodecimal ___ a. 12 b. 8 c. 32 d. None of the above Ans: a. 12 55. The number systems and codes are categorized into how many groups? a. One b. Two c. Three d. Four Ans: a. One 56. The counter is used to count the number of __ a. Digits b. Bits c. Pulses d. None of the above Ans: c. Pulses 57. In how many ways counter can count the pulses? a. One b. Two c. Three d. Four Ans: b. Two 6 RESTRICTED  RESTRICTED 58. What is the formula for the n-bit counter? a. Each state frequency= total frequency/2n b. Each state frequency= total frequency.2n c. Each state frequency= total frequency.2n+1 d. None of the above Ans: a. Each state frequency= total frequency/2n 59). What is the formula to obtain the number of parity bits? a. 2P ? P+m+1 b. 2P ? P+m-1 c. 2P ? P-m-1 d. None of the above Ans: a. 2P ? P+m+1 60. What is the formula to convert any other number system to a decimal number system? a. ?digit*n b. ?digit/npv c. ?digit*npv d. None of the above Ans: c. ?digit*npv 61. The speed of the synchronous counter is ___ a. Higher than asynchronous counter b. Lower than the asynchronous counter c. Equal to asynchronous counter d. None of the above Ans: a. Higher than asynchronous counter 62 How many MOS transistors are required to form SRAM? a. 6-8 b. 4-6 c. 4-8 d. None of the above Ans: a. 6-8 63. Which one belongs to a bipolar saturated logic family? a. Resistor Transistor Logic (RTL) b. Direct Coupled Transistor Logic(DCTL) c. Integration Injection Logic (IIL) d. All of the above Ans: d. All of the above 64. Which one belongs to a unipolar logic family? a. PMOS b. CMOS c. ECL d. Both a and b Ans: d. Both a and b 65. ___ comes under unipolar logic family a. PMOS b. CMOS c. NMOS d. All of the above Ans: d. All of the above 66. The base or radix represents ___ a. Number of bits b. Number of digits c. Number of symbols d. All of the above Ans: d. All of the above 67. What are the complements used for subtraction? a. Binary subtraction b. Hexadecimal subtraction c. BCD & Excess-3 subtraction d. All of the above Ans: d. All of the above 7 RESTRICTED  RESTRICTED 68. DRAM stores single bit by using ____ a. Transistor b. Capacitor c. Both a and b d. None of the above Ans: c. Both a and b 69. The Schottky TTL and ECL (Emitter Coupled Logic) comes under which logic family? a. Bipolar saturated logic family b. Bipolar unsaturated logic family c. Unipolar logic family d. None of the above Ans: b. Bipolar unsaturated logic family 70. The components used in DTL logic are ____ a. Diode, transistor b. Diode, resistor c. Diode, transistor, resistor d. None of the above Ans: c. Diode, transistor, resistor 71. Which code comes under unweighted, sequential, and reflective code? a. Binary code b. Gray code c. Excess-3 d. BCD Ans: c. Excess-3 72. How many MOS transistors are required to form a single cell of DRAM? a. 2 b. 3 c. 4 d. 5 Ans: c. 4 73. Four transistors are required to form a single cell DRAM a. DRAM b. DDRAM c. RAM d. DROM Ans: a. DRAM 74. How much data the shift register can store? a. Only one b. Only two c. Only three d. None of the above Ans: d. None of the above 75. The flip flop is a __ a. 1-bit memory cell b. 2-bit memory cell c. 4-bit memory cell d. 8-bit memory cell Ans: a. 1-bit memory cell 76. The group of flip flops is also known as ____ a. Registers b. Counters c. Encoders d. None of the above Ans: a. Registers 77. The Karnaugh map is developed in which year? a. 1951 b. 1952 c. 1953 d. 1954 Ans: c. 1953 8 RESTRICTED  RESTRICTED 78. The half adder consists ___ a. One input one output b. One input two outputs c. Two inputs two outputs d. Two inputs one output Ans: c. Two inputs two outputs 79. The output of the multiplexer depends on its ___ a. Data outputs b. Data inputs c. Selected inputs d. None of the above Ans: c. Selected inputs 80. ASCII comes under which binary code? a. Alphanumeric b. Reflective c. Sequential d. Error detecting and correcting Ans: a. Alphanumeric 81. The output of the sequential circuit depends on __ a. Present input b. Present input and present state c. Present state d. None of the above Ans: b. Present input and present state 82. Where do all the bios settings and configuration details get to store? a. CMOS b. PMOS c. NMOS d. None of the above Ans: a. CMOS 83. The other names CMOS are ____ a. CMOS memory b. CMOS battery c. Non-volatile BIOS memory d. All of the above Ans: d. All of the above 84. The Field Effect Transistor is ____ device a. Single terminal device b. Double terminal device c. Three terminal device d. None of the above Ans: c. Three terminal device Electronic Measurement and Measuring Instrument 85. Which of the following method of measurement does a bridge circuit uses? a. relative b. comparison c. absolute d. differential Ans: b. comparison 86. Which of the following method is used for the measurement of Medium Resistance? a. Direct-Deflection method b. Anderson Bridge c. Kelvin’s double bridge method d. Carey-Foster bridge method Ans: d. Carey-Foster bridge method 9 RESTRICTED  RESTRICTED 87. Which of the following is the most sensitive detector for single frequency value? a. oscillator b. headphone c. tuned detector d. vibration galvanometer Ans: c. tuned detector 88. Which of the following is a balance equation for computing the resistance? a. R1 = R2 ⁄ R4 b. R1 = R3 ⁄ R4 c. R1 = R2 R3 d. R1 = R2 R3⁄R4 Ans: d. R1 = 2 R3⁄R4 R 89.. Inductance control is obtained by _________ a. using R5 b. using R4 c. using R2 d. using Lx Ans: c. using R2 90. What is the dependence of frequency on the balance equation? a. varies by a factor of 2 b. depends on the detector used c. independent d. depends on the supply magnitude Ans: c. independent 91. Which of the following is the guarding arm? a. capacitance C b. resistance R c. parallel RC combination d. series RC combination Ans: c. parallel RC combination 92. Which of the following can be measured using Maxwell’s Inductance Capacitance Bridge? a. Capacitance b. Frequency c. Mutual Inductance d. Inductance Ans: d. Inductance 93. A multiplier is __________ a. non-capacitive b. capacitive c. non-inductive d. resistive Ans: c. non-inductive 94. The windings of a C.T. are ________ a. tied together b. shorted c. wound over one another d. grounded Ans: c. wound over one another 95. How is the voltage ratio dependent on the frequency? a. they aid each other b. depends on the setup of the circuit c. they are independent of each other d. they oppose each other Ans: d. they oppose each other 96. Increasing secondary burden _____________ a. decreases Is b. keeps Is constant c. decreases Ip d. increases Is Ans: d. increases Is 10 RESTRICTED  RESTRICTED 97. Which of the following device is used to measure power in A.C. circuits? a. ammeter b. wattmeter c. voltmeter d. ohmmeter Ans: c. voltmeter 98. When the moving coil in a Dynamometer type wattmeter deflects ________ a. pointer doesn’t move b. current flows c. voltage is generated d. pointer moves Ans: d. pointer moves 99. What is the effect of capacitance on wattmeter reading? a. opposite to that of resistance b. aiding the capacitance c. aiding the inductance d. opposite to that of inductance Ans: d. opposite to that of inductance 100. Which of the following compares the output in a successive approximation type DVM? a. comparator b. diode c. op amp d. rectifier Ans: a. comparator 101. Which of the following is the main device used in the linear ramp technique? a. non-linear ramp b. linear ramp c. asymptotic ramp d. exponential ramp Ans: b. linear ramp 102. Which of the following determines the rate of measurement cycles? a. multivibrator b. oscillator c. oscilloscope d. amplifier Ans: c. oscilloscope 103. To measure radio frequency the suitable frequency mater is a. Weston frequency meter b. Reed vibrator frequency meter c. Heterodox frequency meter d. Electrical resonance frequency meter Ans: c. Heterodox frequency meter 104. The rectifier instrument is not free from - a. Temperature error b. Wave shape error c. Frequency error d. All of the above Ans: c. Frequency error 105. The operating voltage of meggar is about a. 6v b. 12v c. 40v d.100v Ans: d.100v 106. Why is the scale of a megger calibrated in megaohms? a. to indicate resistance b. to minimise the current flow c. to increase the voltage drop d. to reduce the temperature Ans: a. to indicate resistance 11 RESTRICTED  RESTRICTED 107. Megger can be used for verifying the electrical insulation level of ____________ a. passive components such as resistance, capacitor and inductance b. devices such as motor, cable, etc c. solid state devices d. liquid crystal devices Ans: b. devices such as motor, cable, etc 108. Continuity between any two points can be measured using _________ a. ammeter b. voltmeter c. megger d. galvanometer Ans: c. megger 109. Electrical continuity between any two points exists if _________ a. there is current flow through them b. there is a wire connecting the points c. there is sufficient voltage drop d. pointer shows deflection Ans: d. pointer shows deflection 110. Megger is also known as _________ a. megohmmeter b. multimeter c. galvanometer d. ammeter Ans: a. megohmmeter 111. The application of a megger is _________ a. to measure resistance b. to test for leakage c. to limit the current d. to increase the emf of the circuit Ans: b. to test for leakage 112. How is the megger calibrated? a in steps of 1 unit per division b. based on the value of resistance to be measured c. directly calibrated on the position of the pointer d. reversely calibrated based on the pointer position Ans: d. reversely calibrated based on the pointer position 113. In an ordinary dynamometer, the deflecting torque is _________ a. small b. medium c. large d. very large Ans: c. large 114. Errors are introduced by ________ a. capacitance b. inductance c. resistance d. impedance Ans: b. inductance 115. Power coil has a low value of ________ a. inductance b. capacitance c. resistance d. impedance Ans: c. resistance 116. Low power factor wattmeter are designed to ________ a. have a low torque b. have a high torque c. have a medium torque d. have no torque Ans: a. have a low torque 12 RESTRICTED  RESTRICTED 117. A resistor of 10 kΩ with the tolerance of 5% is connected in parallel with 5 kΩ resistors of 10% tolerance. What is the tolerance limit for a parallel network? a. 9% b. 12.4% c. 8.33% d. 7.87% Ans: c. 8.33% 118. When the bridge is balanced, what is the current flowing through the galvanometer? a. 0 b. depends on the ratio arms R1 and R2 c. varies by a factor of 2 d. depends on the type of null detector used Ans: a. 0 119. An ohmmeters is a …… a. Moving iron instrument b. Moving coil instrument c. Dynamometer instrument d. None of the above Ans: b. Moving coil instrument 120. An induction wattmeter can be used for a. both AC and DC b. DC only c. AC only d. any of the above Ans: b. DC only 121. Potentiometer may be used for a. measurements of instrument b. measurements of current c. calibration of ammeter d. calibration of volunteers e. all of the above Ans: e. all of the above 122. In hot wire instrument the sensing wire is made of a.copper b. silver c. Platinum-iridium d. copper nickel Ans: c. Platinum-iridium 123. In induction meter can handle current up to ….. a.10A b.30A c.60A d.100A Ans: d.100A 124. The pointer of a indicating instrument should be.. a. very light b. very heavy c. either a or b d. neither a or b Ans: a. very light 125. An ammeter is a …. a. Secondary instrument b. absolute instrument c. Recording instrument d. Integrating instrument Ans: a. Secondary instrument 13 RESTRICTED  RESTRICTED 126. Which of the following are integrating instrument…. a. Ammeter b. Voltmeter c. Wattmeter d. Ampere low and watt hour meter Ans: d. Ampere low and watt hour meter 127. Resistance can be measured with the help of a. Wattmeter b. Ohmmeters and resistance bridge c. Voltmeter and Ammeter d. All of the above Ans: d. All of the above 128. A moving iron instrument can be used for.. a. D. C only b. A. C only c. Both D. C and A.c d. None of them Ans: c. Both D. C and A.c 129. For measuring current at high frequency we should be a. Moving iron instrument b. Electrostatic instrument c. Thermocouple instrument d. None of the above Ans: c. Thermocouple instrument 130. The electrical power to a magger is provided by.. a. Battery b. Permanent magnet DC generator c. AC generator d. Any of the above Ans: b. Permanent magnet DC generator 131. Which of the following determines light intersity in CRT.. a. Current b. Fluorescent screen c. Voltage d. Momentum of electroa Ans: d. Momentum of electroa 132. Which of the following oscilloscope is used In a digital storage oscilloscope a. Dual frace b. Conventional c. Multi frace d. Modern Ans: d. Modern 133. Which of the following equation represents mass action law for semiconductors measure in electronic circuits? a. n × p = ni2 b. n × p = ni c. n × p = ni3 d. n × p = ni1/2 Ans: a. n × p = ni2 134. Which of the following method of measurement does a bridge circuit uses? a. relative b. comparison c. absolute d. differential Ans: a. relative Basic Electricity 135. Which of the following is the poorest conductor of electricity? a. Silver b. Copper c. Aluminum d. Carbon Ans: d. Carbon 14 RESTRICTED  RESTRICTED 136. The cells are connected in series to a. Increase the current output b. Increase the voltage output c. Decrease the internal resistance d. Decrease the amount of charging voltage required Ans: d. Decrease the amount of charging voltage required 137. The minimum requirements for causing flow of current are a. A voltage source, a resistor and a switch b. A voltages source and a conductor c. A power source and a bulb d. A voltage source, a conductor an ammeter and a switch Ans: b. A voltages source and a conductor 138. An instrument which detects electric current is known as a. Voltmeter b. Rheostat c. Wattmeter d. Galvanometer Ans: d. Galvanometer 139. Which of the following ampere-second could be the unit? a. Reluctance b. Charge c. Power d. Energy Ans: b. Charge 140. The rating of the fuse wire is always expressed in a. Ampere-hours b. Ampere-volts c. KWH d. Ampere Ans: d. Ampere 141. The S.I. unit of power is a. Henry b. Coulomb c. Watt d. Watt-hour Ans: c. Watt 142. If the battery is wrongly connected on charge following will happen a. Current delivered by the battery will be high b. Current drawing will be Nil c. Currently drawing will be very small d. Currently drawing will be very high Ans: d. Currently drawing will be very high 143. The filament of an electric bulb is made of a. Carbon b. Aluminum c. Tungsten d. Nickel Ans: c. Tungsten 144. The dielectric material used in variable capacitor is generally a. Mica. b. Air. c. Ceramic. d. Electrolyte Ans: b. Air 145. What does a capacitor store? a. Current. b. Charge. c. Voltage. d. Power Ans: b. Charge 15 RESTRICTED  RESTRICTED 146. A capacitor block a. DC. b. AC c. Both AC and DC. d. None of the above Ans: a. DC 147. The type of wiring that is highly suitable for a temporary shed is a. Cleat wiring b. Wooden capping and casing wiring c. Lead sheathed wiring d. Conduit wiring Ans: a. Cleat wiring 148. If the number of resistances are connected in series then the equivalent resistance is a. Decreases. b. Increases. c. Remain same. d. None of the above. Ans: b. Increases. 149. The number of cycle per second is called a. Frequency. b. Time period. c. Angular displacement. d. Angular velocity. Ans: a. Frequency 150. Which of the following is not a passive component? a. Inductor. b. Capacitor. c. Resistor. d. None of the above. Ans: d. None of the above 151. The resistance of a conductor varies inversely as a. Length b. Area of cross-section c. Temperature d. Resistivity Ans: a. Length 152. In Fleming’s left hand rule, middle finger is used to show the direction of __________. a. electric current b. magnetic field c. motion of conductor d. all of these Ans: a. electric current 153. With rise in temperature the resistance of pure metals a. Increases b. Decreases c. Remains constant d. First increases and then decreases Ans: a. Increases 154. The property of the conductor due to which it passes current is called a. Resistance b. Reluctance c. Conductance d. Inductance Ans: c. Conductance 155. The resistance of armature winding depends on a. Length of conductor. b. Cross-sectional area of the conductor. c. Number of conductors. d. All of the above. Ans: d. All of the above 16 RESTRICTED  RESTRICTED 156. A 40 W bulb is connected in series with a room heater. If now 40 W bulb is replaced by 100 W bulb, the heater output will a. Decrease. b. Increase. c. Remain same. d. Heater will burn out. Ans: b. Increase 157. When one leg of parallel circuit is opened out the total current will a. Reduce. b. Increase. c. Decrease. d. Become zero. Ans: c. Decrease 158. Ohm’s law is not applicable to a. Linear circuits. b. Vacuum tubes. c. Carbon resistors. d. High voltage circuits Ans: b. Vacuum tubes 159. All good conductors have high a. Conductance b. Resistance. c. Reluctance. d. Thermal conductivity. Ans: a. Conductance 160. Specific resistance of a conductor depends upon a. Dimensions of the conductor b. Composition of contactor material c. Resistance of the conductor d. Both A and B Ans: d. Both A and B 161. How many cycles will an AC signal make in 2 seconds if its frequency is 100 Hz? a. 50 b. 100 c. 150 d. 200 Ans: d. 200 162. Which of the following is correct about the power consumed by R1 and R2 connected in series if the value of R1 is greater than R2? a. R1 will consume more power b. R2 will consume more power c. R1 and R2 will consume the same power d. The relationship between the power consumed cannot be established Ans: a. R1 will consume more power 163. Which of the following type of circuits in electrical engineering cannot be analyzed using Ohm’s law? a. Unilateral b. Bilateral c. Linear d. Conductors Ans: a. Unilateral 164. The current in each branch of a parallel circuit is proportional to _________ a. The amount of time the circuit is on for b. Proportional to the value of the resistors c. Equal in all branches d. Proportional to the power in the circuit Ans: b. Proportional to the value of the resistors 17 RESTRICTED  RESTRICTED 165. For high frequencies, capacitor acts as _________ a. Open circuit b. Short circuit c. Amplifier d. Rectifier Ans: b. Short circuit 166. How can a magnetic field be produced? a. Using a permanent magnet b. Electric current c. Using a temporary magnet d. Using a permanent magnet or electric current Ans: d. Using a permanent magnet or electric current 167. Magnetic Field lines move from _______ a. North to south b. South to north c. West to east d. East to west Ans: a. North to south 168. The insulating material for cables should a. be acid proof b. be non-inflammable c. be non-hygroscopic d. all above properties Ans: d. all above properties 169. The thickness of insulation layer provided on the conductor, in cables, depends upon a. Operating voltage b. Current to be carried c. Power factor d. both A and B Ans: a. Operating voltage 170. With the rise in temperature, the insulation resistivity of a cable a. Remain unchanged b. Decreases linearly c. Increases linearly d. Reduces exponentially Ans: d. Reduces exponentially 171. In the case of staircase wiring which type of switch is used? a. 2 one way switch b. 1 one way switch c. 2 two way switch d. 1 two way switch Ans: a. 2 one way switch 172. A fuse element should have......... melting point a. High b. Low c. Same d. All of the above Ans: b. Low 173. Which one of these is not a manually operated switch? a. Thumbwheel switch b. Rotary selector switch c. Crossbar switch d. Toggle switch Ans: c. Crossbar switch 174. The earthling wire should have a. High resistance b. Medium resistance c. Negligible resistance d. Any of the above Ans: c. Negligible resistance 18 RESTRICTED  RESTRICTED 175. What is the main purpose of earthing? a. Provide path for leakage current b. Provide electric shock safety c. Provide constant line voltage d. All of the above Ans: d. All of the above 176. The materials used in plate earthing are a. Charcoal b. Salt c. GI wire d. All of the above Ans: d. All of the above 177. In house wiring, black and green wires indicate a. Earth and neutral respectively b. Phase and neutral respectively c. Phase and earth respectively d. Neutral and earth respectively Ans: c. Phase and earth respectively 178. On over charging a battery a. It will bring about chemical change in active materials b. It will increase the capacity of the battery c. It will raise the specific gravity of the electrolyte d. None of the above Ans: d. None of the above 179. A relay is used to a. Break the fault current b. Sense the fault c. Sense the fault and direct to trip the circuit breaker d. All of these Ans: c. Sense the fault and direct to trip the circuit breaker 180. In a lead acid battery, separators are provided a. to avoid internal short circuits b. to reduce internal resistance c. to facilitate flow of current d. to reduce tendency for polarization. Ans: a. to avoid internal short circuits 181. The energy in a lead acid battery is stored in the form of a. Nuclear energy b. Chemical energy c. Non-flowing current d. Electrostatic charge. Ans: b. Chemical energy 182. What is relationship of Power a. P= V x I b. P= IR c. P= V/I d. P=I/R Ans: a. P= V x I 19 RESTRICTED  RESTRICTED 183. what is unit of resistivity a. Ω-m b. Ω c. Ω-m d. Ω-m2 Ans: c. Ω-m Power electronics 184. Power electronics deals with the control of power at a. 50 Hz b. 400 Hz c. 600 Hz d. none of the above Ans: a. 50 Hz 185. The important semiconductor switching devices are.............. a. Oscillator b. triac c. SCR d. both (a) and (b) Ans: d. both (a) and (b) 186. The main types of VSI (Voltage Source Inverter) a. 2 b. 3 c. 4 d. none of the above Ans: d. none of the above 187. Power electronics systems are found in virtually every electronic devices for example a. DC/DC Converters b. AC/DC Converters c. AC/AC Converters d. All of the above Ans: b. AC/DC Converters 188. Disadvantage of power electronics converter a. harmonics b. Low power factor c. Low overload capacity d. All of the above Ans: d. All of the above 189. Step-up chopper is used to obtain a load voltage higher then a. Input Voltage b. Output voltage c. Both (a) & (b) d. None of the above Ans: d. None of the above 190. Application of cyclocontrollers are a. Slip propulsion device b. Mine winders c. Rolling mill drivers d. All of the above Ans: d. All of the above 191. The main types of the cycloconverters a. 2 b. 3 c. 4 d. none of the above Ans: a. 2 20 RESTRICTED  RESTRICTED 192. When a photo diode is used in a optical communication system, all these parameters contributes to the sensitivity of the a. Optical receiver b. Optical Transmitter c. Both (a) & (b) d. None of the above Ans: a. Optical receiver 193. Photo transistor produce a. Current b. Voltage c. Both (a) & (b) d. All of the above Ans: c. Both (a) & (b) 194. The first use of the solar panels or photovoltaic as a power source a. In agriculture for irrigation b. In medicine sector c. In the industry d All of the above Ans: a. In agriculture for irrigation 195. Electronic ballast is a device which controls the a. Starting voltage as listing devices b. Operating current of listing device c. Both (a) & (b) d. None of the above Ans: c. Both (a) & (b) 196. Types of ballast are a. One b. two c. Three d. none of the above Ans: c. Three 197. Electronics ballast takes the supply at a. 50-60 Hz b. 100-220 Hz c. 400-600 Hz d. none of the above Ans: a. 50-60 Hz 198. The voltage blocking capability of the IGBT is determined by the a. Ingestion Layer b. Metal used for the contrast c. Body layer d. Drift layer Ans: a. Ingestion Layer 199. The control parameters in IGBT is the......... a. IG b. VGE c. IC d. VCE Ans: c. IC 200. The three terminals of the IGBT a. Base, Emitter and Collector b. Gate Source and drain c. Gate Emitter and collector d. Base source and drain Ans: c. Gate Emitter and collector 21 RESTRICTED  RESTRICTED 201. A smart grid in an automated fashion to improve the a. Efficiency b. Sustainably of the protection and distribution of electricity c. Reliability d. All of the above Ans: d. All of the above 202. A silicon control rectifier is a a. Uni junction device b. Device with three junction c. Device with four junction d. None of the above Ans: b. Device with three junction. 203. A thyristor is basically a. PNDN device b. Combination of triac c. A set of SCRS d. A set of SCR diac and a triac Ans: a. PNDN device 204. A thyristor equivalent of a theyratron tube is a a. Diac b. Trac c. SCR d. None of the above Ans: c. SCR 205. Which of the following of are the function of athyristor? a. Rectifier and fixed resistor b. Switching device and fixed resistor c. Tuning device and recitations d. Variable resistor and switching device Ans: d. Variable resistor and switching device 206. Number of the diodes required in the ordinary juellware rectifier is a. 1 b. 2 c. 3 d. 4 Ans: b. 2 207. The function of SCR contractor is resistance welding matohingis a. To provide an accurate weld time for each weld b. To connect the large power supply to welding by closing a small switch c. To provide full ware rectification of the welding consest d. To avoid saturation of transformation core Ans: b. To connect the large power supply to welding by closing a small switch 208. By which of the following method dectric power may be transmitted from are location another location a. Underground system b. Over-head system c. Both (a)and (b) d. none of the above Ans: c. Both (a)and (b). 209. Which of the following materials are non used for transmission and distribution of electrical power a. Copper b. Aluminum c. Tungsten d. Steel Ans: c. Tungsten 210. Which of the following constants of the transmission line? a. Inductance b. Capacitance c. Conductance d. All of the above Ans: b. Capacitance 22 RESTRICTED  RESTRICTED 211. The operating voltage of super tension cable is a. 1-11kv b. 11-33kv c. 33-66 kv d. Above 66 kv Ans: b. 11-33kv 212. If the frequency is increased then the skin effect will a. Decrease b. Remain the same c. Increase d. None of the above Ans: c. Increase. 213. Which of the following procedure the radio interference in communication line? a. Electromagnetic Induction b. Electrostatic induction c. Both a & b d. Noneof the above Ans: c. Both a & b 214. Which of the following voltage regulations is considered? a. 10% b. 20% c.100% d. 4% Ans: d. 4% 215. Corona discharge occurs more is a. Humid Weather b. Hot weather c. Cold weather d. Any of the above Ans: a. Humid Weather. 216. A triac is a.......... switch a. bidirectional b. unidirectional c. mechanical d. none of the above Ans: a. bidirectional 217. A diac has....... switch a. an AC b. a DC c. a mechanical d. none of the above Ans: a. an AC. 218. A UJT has.............. a. two pin junction b. one pin junction c. three pin junction d. none of the above Ans: a. two pin junction 219. A UJT is sometimes called............... diode a. low resistance b. high resistance c. single- base d. double-based Ans: d. double-based 220. Power electronics essentially deals with control of a.c power at a. frequency above 20 kHz b. frequency above 1000 kHz c. frequency above 10 kHz d. 50 kHz frequency Ans: d. 50 kHz frequency 221. When the temperature increases, the inter base resistance (RBB) of a UJT.......... a. increases b. decreases c. remains the same d. none of the above Ans: b. decreases 23 RESTRICTED  RESTRICTED 222. The triacis............... a. Like a bidirectional SCR b. a four-terminal device c. not a thyristor d. Answer a & b Ans: a. Like a bidirectional SCR 223. To display the digit 8 in a seven-segment indicator a. C must be lighted b. G must be off c. F must be on d. All segments must be lighter Ans: d. All segments must be lighter. 224. When the light increases, the reverse current in a photo-diode a. increases b. decreases c. is unaffected d. none of the above Ans: a. increases 225. The most inexpensive switch is …. switch a. electronic b. mechanical c. electromechanical d. none of the above Ans: a. electronic 226. The main disadvantage of a mechanical switch is that it.......... a. is operated mechanically b. is costly c. has high inertia d. none of the above Ans: a. is operated mechanically 228. When a transistor is driven to cut off, ideally the output is a. VCC b. 0 c. VCC/2 d. VCC/3 Ans: a. VCC 229. In a radio receiver, noise is generally developed at.......... a. IF stage b. receiving antenna c. audio stage d. RF stage Ans: d. RF stage 230. A Zener diode utilises.......... characteristic for voltage regulation a. forward b. reverse c. both forward and reverse d. none of the above Ans: c. both forward and reverse 231. Zener diode are generally made of.......... a. germanium b. silicon c. carbon d. none of the above Ans: b. silicon 232. A relay is superior to a mechanical switch because it.......... a. is relatively inexpensive b. does not require moving contacts c. combines control with power amplification d. none of the above Ans : c. combines control with power amplification 24 RESTRICTED  RESTRICTED 233. If a square wave is fed to a differentiating circuit, the output will be.......... a. sine wave b. sharp narrow pulses c. rectangular wave d. triangular wave Ans: b. sharp narrow pulses 234. A diac has....... terminal a. 2 b. 3 c. 4 d. none of the above Ans: a.2 235. Which of the given device is the fastest switching device a. MOSFET b. Triode c. BJT d. JEFT Ans: b. Triode 236. A snubber circuit is used to a. Limit the rate of rising in voltage across BJT b. Limit the rate of rising in voltage across SCR c. Limit the rate of rising in current across TRIAC d. Limit the rate of rising in current across BJT Ans: b. Limit the rate of rising in voltage across SCR 237. If the maximum value of applied voltage for a full-wave center ap (M-2) rectifier is 30 V, find the magnitude of ripple voltage a. 83.88 b. 84.52 c. 87.62 d. 89.59 Ans: c. 87.62 238. In the forward blocking mode of a silicon controlled rectifier, the SCR is a. In on state b. In natural state c. Forward biased state d. In off state Ans: d. In off state 239. A silicon controlled rectifier is turned on if the anode current is greater than a.Trigger current b. Anode current c. Cathode current d. Holding current Ans: b. Anode current 240. The anode current passing through a conducting silicon-controlled rectifier is 20 A. If its gate current is made half, what will be the anode current? a.10 A b. 20 A c. 5 A d. 30 A Ans: b. 20 A 25 RESTRICTED  RESTRICTED 241. A silicon controlled rectifier is turned off mode when its turn off time is a. Greater than the circuit turn off time b. Less than the circuit turn off time c. Equal to the circuit turn off time d. None of these Ans: b. Less than the circuit turn off time 242. A 1 - ∅ full-wave rectifier is made by using thyristors. If the peak value of the sinusoidal input voltage is Vm and the value of the delay angle is ?/4 radian, find the average value of output voltage a. 0.25 VM b. 0.45 VM c. 0.65 VM d. 0.85 VM Ans: b. 0.45 VM 243. The TRIAC is the same as a. Two SCR connected in parallel b. Two SCR connected in antiparallel c. One SCR and one thyristor connected in parallel d. Two SCR connected in series Ans: b. Two SCR connected in antiparallel 244. A half-wave rectifier circuit using an ideal diode has an input voltage of 10 sin ?t V; find the average and RMS value of output voltage? a. 3.18 V, 5V b. 3.68 V, 8V c. 4.18 V, 5V d. 4.68 V, 8V Ans: a. 3.18 V, 5V 245. A solar cell of 450 V supplies power to an ac source of 440 V, 50 Hz through a 3 phase fully controlled bridge converter. An inductance with a value of 10 A is connected to the dc circuit to maintain the dc current. If the resistance of the solar cell is 1 Ω, each thyristor will be reverse biased for a period of a. 1480 b. 1380 c. 1280 d. 1180 Ans: b. 1380 246. A 1 - ∅ full wave rectifier is designed using thyristors. It the peak value of the sinusoidal input voltage Vm and the delay angle is radian, find the average value of output voltage? a.0.35 Vmax b. 0.45 Vmax c. 0.55 Vmax d. 0.65 Vmax Ans: c. 0.55 Vmax 247. Which of the given device is the most suitable power device for a higher frequency (above 100 kHz) switching application a. SCR b. Power MOSFET c.GTO d. BJT Ans: b. Power MOSFET 26 RESTRICTED  RESTRICTED 248. A freewheeling diode is phase-controlled rectifiers. a. Stops rectifier operations b. Improves line power factor c. Is the reason for additional harmonics d. Is the reason for the sudden breakdown Ans: b. Improves line power factor 249. In a three-phase bridge rectifier, the maximum conduction of each thyristor is a.1200 b. 900 c. 300 d. 600 Ans: a.1200 250. In a 3-∅ controlled bridge rectifier, the frequency of ripple in the output voltage depends on a. Power factor b. Supply frequency c. Voltage source d. Firing angle Ans: b. Supply frequency Electrical Engineering 251 Which of the following law/rule can he used to determine the direction of rotation of D.C. motor ? a. Lenz’s law b. Faraday’s law c.Coloumb’s law d. Fleming’s left-hand rule Ans: d. Fleming’s left-hand rule 252. Which of the following load normally needs starting torque more than the rated torque? a. Blowers b. Conveyors c. Air compressors d. Centrifugal pumps Ans: b. Conveyors 253. The starting resistance of a D.C. motor is generally a. low b. around 500 Q c. 1000 Q d. infinitely large Ans: a. low 254. The speed of a D.C. series motor is a. proportional to the armature current b. proportional to the square of the armature current c. proportional to field current d. inversely proportional to the armature current Ans: d. inversely proportional to the armature current 255. In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to a. 00% of the previous value b. 50% of the previous value c. 25% of the previous value d. 10% of the previous value Ans: c. 25% of the previous value 256. The current drawn by the armature of D.C. motor is directly proportional to a. the torque required b. the speed of the motor c. the voltage across the terminals d. none of the above Ans: a. the torque required 27 RESTRICTED  RESTRICTED 257. The power mentioned on the name plate of an electric motor indicates a. the power drawn in kW b. the power drawn in kVA c. the gross power d. the output power available at the shaft Ans: d. the output power available at the shaft 258. Which D.C. motor has got maximum self-loading property? a. Series motor b. Shunt motor c. cumulatively compounded ‘motor d. differentially compounded motor Ans: d. differentially compounded motor 259. Which D.C. motor will be suitable along with flywheel for intermittent light and heavy loads? a. Series motor b. Shunt motor c.Cumulatively compounded motor d. Differentially compounded motor Ans: c. Cumulatively compounded motor 260. A D.C. series motor is that which a. has its field winding consisting of thick wire and less turns b. has a poor torque c. can be started easily without load d. has almost constant speed Ans: a. has its field winding consisting of thick wire and less turns 261. For starting a D.C. motor a starter is required because a. it limits the speed of the motor b. it limits the starting current to a safe value c. it starts the motor d. none of the above Ans: b. it limits the starting current to a safe value 262. The type of D.C. motor used for shears and punches is a. shunt motor b. series motor c. differential compoutid D.C. motor d. cumulative compound D.C. motor Ans: d. cumulative compound D.C. motor 263. If a D.C. motor is connected across the A.C. supply it will a. run at normal speed b. not run c. run at lower speed d. burn due to heat produced in the field winding by.eddy currents Ans: d. burn due to heat produced in the field winding by.eddy currents 264. To get the speed of D.C, motor below the normal without wastage of electrical energy is used. a. Ward Leonard control b. rheostat control c. any of the above method d. none of the above method Ans: a. Ward Leonard control 265. When two D.C. series motors are connected in parallel, the resultant speed is a. more than the normal speed b. loss than the normal speed c. normal speed d. zero Ans: a. more than the normal speed 266. The speed of a D.C. shunt motor more than its full-load speed can be obtained by a. decreasing the field current b. increasing the field current c. decreasing the armature current d. increasing the armature current Ans: a. decreasing the field current 28 RESTRICTED  RESTRICTED 267. In a D.C. shunt motor, speed is a. independent of armature current b. directly proportional to the armature current c. proportional to the square of the current d. inversely proportional to the armature current Ans: a. independent of armature current 268. A direct on line starter is used: for starting motors a. up to 5 H.P. b. up to 10 H.P. c. up to 15 H.P. d. up to 20 H.P. Ans: a. up to 5 H.P. 269. What will happen if the back e.m.f. of a D.C. motor vanishes suddenly? a. The motor will stop b. The motor will continue to run c. The armature may burn d. The motor will run noisy Ans: c. The armature may burn 270. In case of D.C. shunt motors the speed is dependent on back e.m.f. only because a. back e.m.f. is equal to armature drop b. armature drop is negligible c. flux is proportional to armature current d. flux is practically constant in D:C. shunt motors Ans: d. flux is practically constant in D:C. shunt motors 271. In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be a. almost negligible b. rated full-load current c. less than full-load current d. more than full-load current Ans: d. more than full-load current 272. These days D.C. motors are widely used in a. pumping sets b. air compressors c. electric traction d. machine shops Ans: c. electric traction 273. By looking at which part of the motor, it can be easily confirmed that a particular motor is D.C. motor? a. Frame b. Shaft c. Commutator d. Stator Ans: c. Commutator 274. In which of the following applications D.C. series motor is invariably tried? a. Starter for a car b. Drive for a water pump c. Fan motor d. Motor operation in A.C. or D.C. Ans: a. Starter for a car 275.` In D.C. machines fractional pitch winding is used a. to improve cooling b. to reduce copper losses c. to increase the generated e.m.f. d. to reduce the sparking Ans: d. to reduce the sparking 276. A three point starter is considered suitable for a. shunt motors b. shunt as well as compound motors c. all D.C. motors d. shunt, compound and series motors Ans: b. shunt as well as compound motors 29 RESTRICTED  RESTRICTED 277. In case-the conditions for maximum power for a D.C. motor are established, the efficiency of the motor will be a. 100% b. anywhere between 75% and 90% c. around 90%. d. less than 50% Ans: d. less than 50% 278. The ratio of starting torque to full-load torque is least in case of a. series motors b. shunt motors c. compound motors d. none of the above Ans: b. shunt motors 279. In D.C. motor which of the following can sustain the maximum temperature rise? a. Slip rings b.Commutator c. Field winding d. Armature winding Ans: c. Field winding 280. No-load speed of which of the following motor is highest? a. Differentially compound motor b. Cumulative compound motor c. Series Motor d. Shunt Motor Ans: c. Series Motor 281. Which of the following rule is used to determine the direction of rotation of D.C motor? a. Columb’s Law b. Lenz’s Law c. Fleming’s Right-hand Rule d. Fleming’s Left-hand Rule Ans: d. Fleming’s Left-hand Rule 282. Which part of the DC motor can sustain maximum temperature rise? a.Armature Winding b.Field winding c.Slip Ring d.Commutator Ans: d.Commutator 283. The efficiency of the DC motor at maximum power is a.90% b.100% c.Around 80% d. Less than 50% Ans: d.Less than 50% 284. In which of the following applications DC series motor is used? a.Centrifugal Pump b.Motor Operation in DC and AC c.Water pump drive d.Starter for car Ans: d.Starter for car 285. Nowadays DC motor is widely used in a.Electric Traction b.Air compressor c.Centrifugal Pump d. Machine shop Ans: a.Electric Traction 286. Which DC motor has the least percentage increase in Input current for the same percentage increase in torque? a. Separately excited motor b. Series motor c. Shunt motor d. Compound motor Ans: b. Series motor 287. By looking at which particular part of the motor we can Identify a “DC motor”? a. Shaft b.Field winding c. Commutator d.Armature winding Ans: c.Commutator 30 RESTRICTED  RESTRICTED 288. Counter EMF of the DC motor is a. Less than the applied voltage b. More than the applied voltage c. Equal to the applied voltage d. None of the above Ans: a.Less than the applied voltage 289. If the back EMF of DC motor vanishes then a. The motor continues to run b. Motor will stop c. Armature will burn d. The motor continues to run at slow speed Ans: c. Armature will burn 290. Why is the speed of DC shunt motor dependent on Back EMF? a. Because flux is proportional to the armature current b. Because armature drop is negligible c. Because Back EMF is equal to armature current d. Because flux is constant in DC shunt motor Ans: d. Because flux is constant in DC shunt motor 291. What will happen when the field of a DC shunt motor gets opened while the motor is running? a. Continue to run at the same speed b. Speed of motor will be reduced c. The motor will attain dangerous high speed d. Armature current will be reduced Ans: c. The motor will attain dangerous high speed 292. Which of the following DC motor have the tendency of load instability? a. Cumulative compound motor b. Shunt Motor c. Series motor d. Differentially compound motor Ans: d. Differentially compound motor 293. The reason for using starter while starting of DC motor is a. To restrict armature current as there is no back E.M.F at starting b. Motors are not self-starting c. Restrict starting torque d. None of the above Ans: d. Differentially compound motor 294. The capacity of a battery is expressed in terms of a. Current rating b. Voltage rating c. Ampere hour rating d. None of the above Ans: c. Ampere hour rating 295. The storage battery generally used in electric power station is a. Nickel-cadmium battery b. Zinc carbon battery c. (c)Lead-acid battery d. (d)None of the above Ans: c. Lead-acid battery 31 RESTRICTED  RESTRICTED 296. Trickle charger of a storage battery helps to a. Maintain proper electrolyte level b. Increase its reverse capacity c. Prevent sulphation d. Keep it fresh and fully charged Ans: d. Keep it fresh and fully charged 297. Battery charging equipment is generally installed a. In well ventilated location b. In clean and dry place c. As near as practical to the battery being charged d. In location having all above features Ans: d. In location having all above features 298. The efficiency of the DC motor at maximum power will be a. 100% b. Anywhere between 75% and 90% c. Around 90% d. Less than 50% Ans: d. Less than 50% 299. The hysteresis loss in a DC machine least depends on a. Frequency of magnetic reversals b. Maximum value of flux density c. Volume and grade of iron d. Rate of flow of ventilating air Ans: d. Rate of flow of ventilating air 300. Which of the following is not the effect of iron loss? a. Loss of efficiency b. Excessive heating of core c. Increase in terminal voltage d. Rise in temperature of ventilating air Ans: c. Increase in terminal voltage Electronics Device & Circuit-I 301. An ideal voltage source has.........internal resistance. a. small b. large c. infinite d. zero Ans: d. zero 302. Efficiency at maximum power transfer is.... a. 75% b. 25% c. 90% d. 50% Ans: d. 50% 303. The output voltage of an ideal voltage source is... a. Zero b. Constant c. Depend on load resistance d. Depend on internal resistance Ans: b. Constant 304. The practical example of ideal voltage source is a. Lead-acid cell b. Dry cell c. Daniel cell d. None of the above Ans: a. Lead-acid cell 32 RESTRICTED  RESTRICTED 305. Maximum power will be transferred from a source of 10 Ω resistance to a load of...... a. 5 Ω b. 20 Ω c. 10 Ω d. 40 Ω Ans: c. 10 Ω 306. When the conductor orbit of an atom has more than 4 electrons, the material is generally a.. a. metal b. non-metal c. semiconductor d. None of the above Ans: b. non-metal 307. The power supply in a radio receiver generally uses......filter. a. capacitor input b. choke input c. resistance d. none of the above Ans: d. none of the above 308. The solid state equivalent of cold cathode diode is..... a. Zenerdiode b. crystal diode c. LED d. transistor Ans: a.Zenerdiode 309. A semiconductor is formed by.....bonds. a. covalent b. electrovalent c. co-ordinate d. none of the above Ans: a. covalent 310. A pentavalent impurity has......valence electronics. a. 3 b. 5 c. 4 d. 6 Ans: b. 5 311. An –type semiconductor is.... a. Positively charge b. negatively charge c. Electrically natural d. None of the above Ans: c. Electrically natural 312. The random motion of holes and free electrons due to thermal agitation is called.... a. diffusion b. pressure c.ionisation d. none of the above Ans: a. diffusion 313. A forward biased PN junction has a resistance of the... a. order of Ω b. order of kΩ c. order of MΩ d. none of the above Ans: a. order of Ω 314. A reverse biased PN junction has resistance of the a. order of Ω b. order of kΩ c. order of MΩ d. none of the above Ans: c. order of MΩ 33 RESTRICTED  RESTRICTED 315. The leakage current in a PN junction is of the order of.... a. A b.mA c. kA d.uA Ans: d.uA 316. The cut-in voltage for silicon diode is approximately a. 0.2 V b. 0.6 V c. 1.1 V d. 1.4 V Ans: b.0.6 V 317. The electrical resistance of the depletion layer is large because a. It has no change carriers b. It has a large number of charge carriers c. It contains electrons as charge carriers d. It has holes as charge carriers Ans: a.It has no change carriers 318. If the forward voltage in a semiconductor diode is doubled, the width of the depletion layer will a. Become half b. Become one-fourth c. Remain unchanged d. Become double Ans: a. Become half 319. The PN junction diode is used as a. An amplifier b. A rectifier c. An oscillator d. A modulator Ans: b.A rectifier 320. When a PN junction diode is reverse biased a. Electrons and holes are attracted towards each other and move towards the depletion region b. Electrons and holes move away from the junction depletion region c. Height of the potential barrier decreases d. No change in the current takes place Ans: b.Electrons and holes move away from the junction depletion region 321. A PN junction has a thickness of the order a. 1 cm b. 1 mm c. 10-6 m d. 10-12 Ans: c.10-6 m 322. In the depletion region of an unbiased PN junction diode there are a. Only electrons b. Only holes c. Both electrons and holes d. Only fixed ions Ans: d.Only fixed ions 323. On increasing the reverse bias to a large value in a PN junction diode, current a. Increases slowly b. Remains fixed c. Suddenly increases d. Decreases slowly Ans: c.Suddenly increases 34 RESTRICTED  RESTRICTED 324. The number of depletion layers in a transistor is ………… four b. three one d. two Ans: d. two 325. A transistor is essentially a_______ a. voltage operated device b. resistance operated device c. current operated device d. power operated device Ans : c. current operated device 326. A transistor can be used as_______ a fullwave rectifier b. an amplifier c. a halfwave rectifier d. an insulator Ans: b. an amplifier 327. The part of a transistor which is heavily doped to produce a large number of majority carriers is the_____________ a. collector b. emitter c. base d. near both the junctions Ans: b.emitter 328. In a transistor an emitter base junction is always_________ a. reversed biased b. grounded c. forward biased d. unbiased Ans: c.forward biased 329. In a p-n-p transistor, thep-type semiconductor acts as__________ a. an emitter b. a collector c. base d. either an emitter or a collector Ans: d. either an emitter or a collector 330. Transistors are prepared from___________ a. metals b. insulators c. intrinsic semiconductors d. doped semiconductors Ans: d.doped semiconductors 331. In an n-p-n transistor, the n region acts__________ a. only as an emitter b. only as a collector c. only as a base d. either as an emitter or a collector Ans: d.either as an emitter or a collector 332. A single stage transistor amplifier contains ……………. and associated circuitry a. Two transistors b. One transistor c. Three transistor d. None of the above Ans: b.One transistor 333. The phase difference between the output and input voltages of a CE amplifier is ……………….. a. 180o b. 0o o c. 90 d. 270o o Ans: a.180 35 RESTRICTED  RESTRICTED 334. When an a.c. signal is applied to an amplifier, ,the operating point moves along ……………. a. d.c. load line b. a.c. load line c. both d.c. and a.c. load lines d. none of the above Ans: b.a.c. load line 335. In the zero signal conditions, a transistor sees ……………….. load a. d.c. b. a.c c. bothd.c. and a.c. d. none of the above Ans: a. d.c 336. A single stage transistor amplifier contains ……………. and associated circuitry a. Two transistors b. One transistor c. Three transistor d. None of the above Ans: b.One transistor 337. The phase difference between the output and input voltages of a CE amplifier is ……………….. a. 180o b. 0 o c. 90o d. 270o o Ans: a.180 338. It is generally desired that a transistor should have …………….. input impedance a. Low b. Very low c. High d. Very high Ans : c.High 339. The input capacitor in an amplifier is the ……………….. capacitor a. Coupling b. Bypass c. Leakage d. None of the above Ans: a. Coupling 340. A large number of free electrons exist in..... a. Semiconductor b. Metals c. Insulators d. Non-metals Ans: b.Metals 341. The maximum efficiency of a half-wave rectifier is...... a. 20.3% b. 80.6% c. 50% d. 40.6% Ans: d.40.6% 342. In a conductor, the energy band between valence and conduction bands is...... a. large b. very large c. very small d. none of the above Ans: a.large 343. A semiconductor has temperature co-efficient of resistance. a. positive b. zero c.Negative d. none of the above Ans: c.Negative 36 RESTRICTED  RESTRICTED 344. In a semiconductor, current conduction is due.... a. only to holes b. only to free electrons c. to holes and free electrons d. none of the above Ans: c.to holes and free electrons 345. A PN junction act as a.... a. controlled switch b. bidirectional switch c. unidirectional switch d. none of the above Ans: c.unidirectional switch 346. The leakage current across a PN junction is due to.... a. minority carriers b. majority carriers c. junction capacitance d. none of the above Ans: a.minority carriers 347. With forward bias to a PN junction, the width of depletion layer..... a. decreases b. increase c. remains the same d. none of the above Ans: a.decreases 348. The leakage current across a PN junction is due to.... a. minority carriers b. majority carriers c. junction capacitance d. none of the above Ans: a. minority carriers 349. With forward bias to a PN junction, the width of depletion layer..... a. decreases b. increase c. remains the same d. none of the above Ans: a. decreases 350. The phase difference between the output and input voltages of a CE amplifier is ……………….. a.180o b. 0o o c. 90 d. 270o o Ans: a.180 Electronics Device & Circuit-II 351. What stands for UJT? a.Unidirectional Transistor b. Unipolar transistor c. Unijunction Transistor d. none of them Ans: a.Unijunction Transistor 352. UJT has------ a. 3 terminal b. 2 terminal c. 4 terminal d. no terminal Ans: a.3 terminal 37 RESTRICTED  RESTRICTED 353. UJT is a------------ absorbing device. a. low power b. High power c. very high power d. very low power Ans: a.low power 354. How many base of UJT? a. 4 b. 2 c. 5 d. 3 Ans: b. 2 355. UJT may be better used as – a. Amplifier b. Clamper c. Rectifier d. Saw-tooth generator Ans: d. Saw-tooth generator 356. How many pn junction of SCR? a.4 b. 2 c. 5 d. 3 Ans: b. 2 357. An SCR has Three terminal such as--------- a.Cathode, anode, gate b.Cathode, anode, drain c.Cathode, anode, grid d.none of them Ans: a. Cathode, anode, gate 358. An SCR is sometimes called --------------- a. Triac b.Diac c. UJT d.Thyristor Ans: d.Thyristor 359. An SCR is made of ---------- a. Germanium b. Silicon c. carbon d. none of them Ans: b. Silicon 360. In normal operation of an SCR, gate is ------------- with respect to cathode. a.Positive b. Negative c. At zero potential d.none of them Ans: a. Positive 361. The controlled element of an SCR is--------- a.Cathode b. Anode c. Anode supply d. Gate Ans: d. Gate 362. When SCR is turned ON, the voltage across it is about ----------- a. Zero b. 10V c. 1V d. 2V Ans: c. 1V 363. An SCR is a ----------- triggered device. a. Voltage b. Current c. both of them d. none of them 38 RESTRICTED  RESTRICTED Ans: b. Current 364. An SCR combines the features of --- a. A rectifier and resistance b.A rectifier and transistor c.A rectifier and capacitor d. none of them Ans: b.A rectifier and transistor 365. An SCR has ----------- semiconductor layer. a.4 b. 2 c. 5 d. 3 Ans: a. 4 366. How many types of poly phase rectifier? a. 4 b. 2 c. 5 d. 3 Ans: b. 2 367. What stands for PUT? a. Program Uni-junction transistor b. Program unidirectional transistor c. Programmable unidirectional transistor d. Programmable uni-junction transistor. Ans: d. Programmable uni-junction transistor. 368. PUT is used mainly in --------- a.multivibrator b. amplifier c. Time delay logic and SCR d. none of them Ans: c. Time delay logic and SCR 369. How many junction and layer of PUT? a.3 junction and 4 layer b. 3 junction and 3 layer c.4 junction and 3 layer d. none of them Ans: a.3 junction and 4 layer 370. How many terminals in DIAC? a.4 b.2 c. 5 d. 3 Ans: b.2 371. Which of the following is used for turning on DIAC? a. High voltage on anode b. Break over voltage c. Gate voltage d. Gate current Ans: b. Break over voltage 372. Which power semiconductor device is not having the gate terminal? a.JFET b. IGBT c. TRAIC d.) DAIC Ans: d. DAIC 39 RESTRICTED  RESTRICTED 373. How many terminals in TRIAC? a.4 b. 2 c. 5 d.3 Ans: d.3 374. How many doped regions do a standard TRIAC have? a.4 b. 6 c. 5 d. 3 Ans: b. 6 375. How many semiconductor does a TRIAC? a.4 b. 2 c. 5 d. 3 Ans: a. 4 376. Clamping is a process of introducing a/an------ a. dc level into an ac signal b. ac level into an ac signal c. ac level into a dc signal d. dc level into a dc signal Ans: a. dc level into an ac signal 377. Digital storage oscilloscope is used to measured amplitude of--- a. Sinusoidal b. Triangular c. Saw tooth d. All of them Ans: d.All of them 378. In a digital clock constant frequency pulse is generated by ----- a. Blocking oscillator b. Astable multivibrator c. Bistable multivibrator d. Mono stable multivibrator Ans: b.Astable multivibrator 379. The pulse duration of a waveform is 4ms and its decay time is 2ms then its rise time is---- a.1ms b.2ms c.5ms d. 3ms Ans: b2ms 380. An astablemultivibrator produces ---------- a. Sine wave b. Triangular wave c. Saw tooth wave d. Square wave Ans: d. Square wave 381. Which of the following cannot be fabricated on an IC? a.Diodb. b. Resistor c.Large inductor and transformer d. Transistor Ans: c.Large inductor and transformer 382. Integrated circuits are generally made of ---- a. Copper b.Silicon c. Germanium d. None of them Ans: b. Silicon 40 RESTRICTED  RESTRICTED 383. Which of the following IC is most commonly used? a.Hybrid b. Thin film c. monolithic c. none of them Ans: c. monolithic 384. What is the most popular form of the IC package? a.Flatpack b. DIL c. TO-5 d. All of them Ans: a.Flatpack 385. Which are the active component in an IC? a.Resistor b. Capacitor c. Transistor &Diode d. all of them Ans: d. all of them 386. Which kind of integrated circuit is suitable for small quantity custom circuits? a. Linear IC b. monolithic IC c. Digital IC d.Hybrid IC Ans: d. Hybrid IC 387. An Identical OP-AMP is supposed to have----- a. Infinite input impedance b. Zero output impedance c.Infinite bandwidth d. all of them Ans: d.all of them 388. Which of the following is an operational amplifer? a. IC 8085 b. IC 741 c. IC 7805 d. IC 555 Ans: b. IC 741 389. An instrumentation amplifier has a high---------- a. Output impedance b. Power gain c. CMRR d. Supply Voltage Ans: c. CMRR 390. An operational amplifier as a voltage follower has a voltage gain of---------- a.Unity b. Infinity c. Zero d. Less than unity Ans: a. Unity 391. Antransconductance amplifier is also called ------- a. Current to voltage converter b. Voltage to current converter c. resistor d. inductor Ans: a. Current to voltage converter 392. The source terminal of a JFET corresponds to ------------ of a vacuum tube. a.Plate b.Cathode c. Grid d. Anode Ans: b.Cathode 393. The channel of a JFET is between the ------------ a. Gate and drain b. Gate and Source c. Drain and source d. input and output Ans: c. Drain and source 41 RESTRICTED  RESTRICTED 394. MOSFET from a JFET differs mainly because of ----------- a. Power rating b. the output c. the JFET has an pn junction d. the MOSFET has two gates. Ans: c. the JFET has an pn junction 395. Which is not considered as linear voltage regulator? a. Fixed output voltage regulator b. Adjustable output voltage regulator c.Special regulator d.Switching regulator Ans: d.Switching regulator 396. To get maximum output current IC regulation are provided with-------- a. Radiation Source b. Heat Sink c. Peak Ditector d. none of them Ans: b. Heat Sink 397. Push-pull amplifier circuit is used as------- a. Power amplifier b. Audio amplifier c. RF amplifier d. Emitter follower Ans: a. Power amplifier 398. The breakdown voltage in power BJT depends on----- a. Collector current b. Base emitter junction thickness c. Base current d.Drift region thickness Ans: d.Drift region thickness 399. What do you mean by LM 78XX? a. Positive voltage regulator IC b. Negative voltage regulator IC c. both of them d. none of them Ans: a.Positive voltage regulator IC 400. What do you mean by LM 79XX? a. Positive voltage regulator IC b.Negative voltage regulator IC c. both of them d. none of them Ans: b.Negative voltage regulator IC Electronics Equipment and system 401. What is the full form of PA system in audio devices? a. Public address b. Phase action c. Power action d. Public action Ans: a.Public address 402. Which types of system in the PA system in audio device? a. Electroacoustic b. Electro dynamic c. Electromagnetic d.Piezo-electric Ans: a.Electroacoustic 42 RESTRICTED  RESTRICTED 403. To which stage is the output of microphone fed in PA system? a. Voltage amplifier b.Loud speaker c Power amplifier d. Mixer Ans: d.Mixer 404. How many types of mixers are there in a PA system in audio devices? a. 1 b. 2 c. 3 d. 4 Ans: b.2 405. Which amplifier uses push pull type amplifier circuit in a PA system? a. Power amplifier b. Voltage amplifier c. Drive amplifier d. Frequency amplifier Ans: a.Power amplifier 406. Modulation is done in_______________ a. Transmitter b. Between transmitter and radio receiver c. Radio receiver d. None of the above Ans: a. Transmitter 408. In a transmitter________________Oscillator is used? a.Hartly b. RC phase shift c. Wien-bridge d. Crystal Ans: d.Crystal 409. In an AM wave useful power is carrier by a. Carrier b. Sidebands c. BAR Sidebands & carrier d. None of the above Ans: b.Sidebands 410. In amplitude modulation, bandwidth is ______________the audio signal frequency. a. Three b.Four times c. Twice d. None of the above Ans: c.Twice 411. In amplitude modulation, the ______________of carrier is varied according to the strength of the signal. a. Amplitude b. Frequency c. Phase d. None of the above Ans: a.Amplitude 412. Demodulation is done in __________________ a. Receiving antenna b. Transmitter c. Radio receiver d. Transmitting antenna Ans: c.Radio receiver 413. In a radio receiver noise is generally developed at a. IF stage b. Receiving antenna c. Audio stage d. RF stage Ans: b.Receiving antenna 415. Manmade noise are _____________ variations a. Amplitude b. Frequency c. Phase d. Both phase and frequency Ans: a.Amplitude 43 RESTRICTED  RESTRICTED 416. The major advantages of FM over AM is a. Reception is less noisy b. Higher carrying frequency c. Smaller bandwidth d. Small frequency deviation Ans: a.Reception is less noisy 417. In a radio receiver, we generally use___________________oscillator as a local oscillator. a. Crystal b. Wien-bridge c. Phase-shift d. Hartley Ans: d.Hartley 418. Satellite generates which types of signals? a. Visible rays b. X-rays c. Cosmic waves d. Radio waves Ans: d. Radio waves 419. GPS user solution depends on which of the following? a. Absolute positioning b. Satellite vehicle c. Space vehicle d. Relative positioning Ans: c.Space vehicle 420. Which is the main parameter use in pseudo ranging? a. Time b. Display c. Velocity d. Frequency Ans: a.Time 421. Which of the following is having same principle as that of determining the position in GPS? a. Compass b. Traversing c. Trisection d. Re-section Ans: d.Re-section 422. Which among the following is use to locate an object? a. GPS b. GIS c. RS d. IRS Ans: a.GPS 423. What of the following can indicate the correct set of GPS segments? a. Navigation, space b. User, Navigation c. Control, User d. Control, Navigation Ans: c.Control, User 424. Which of the following segments can use GPS receiver? a. Navigation segment b. Space segment c. Control segment d. User segment Ans: d.User segment 425. Which of the following indicate the functioning of the space segments? a. Navigation signals b. Space signals c. User signals d. Control signals Ans: a.Navigation signals 44 RESTRICTED  RESTRICTED 426. What stands for ICS? a. Internal communication system b. Integrated communication system c. International communication system d. None of the above Ans: b. Integrated communication system 427. What stands for BTS? a. Base terminal server b. Bus terminal server c. Bus terminal system d. Base thermal system Ans: b.Bus terminal server 428. What stand for VDU? a. Vital Display Unit b. Visual display unit. c. Variable display unit. d. Video display unit. Ans: d. Video display unit. 429. How many CCU are held in ICS of BNS Bangabandhu? a. 2 b. 3 c. 4 d. 5 Ans: C.4 430. What is the meaning of CFA? a. Cross field Amplifier. b. Carries field Amplifier. c. Carrier frequency Amplifier. d. Cross field Amplifier. Ans: a. Cross field Amplifier. 431. What is magnetron? a. High Power high frequency oscillator. b. Microwave reducer. c.Low power high frequency Amplifier. d. Low power wideband Amplifier. Ans: a. High Power high frequency oscillator. 432. What stands for TWT? a. Traveling wave tube. b. Trace wave tube. c. Travelling wave guide Tube. d. Tone wave Tone Ans: a. Traveling wave tube. 433. What stand for AGC? a. Auto Gained control. b. Automatically gain control. c. Automatic Gain control. d. Automatic Gain communication. Ans: c. Automatic Gain control. 434. Radar principle is used in a. Detection of aircraft. b. Telephony. c. Electron Microscope. d. all of the above. Ans: a. Detection of aircraft. 435. Which factor determines the range regulation of radar? a.Size of the antenna. b. Bandwidth of the transm