electrical engineering Mcqs
1. economics of power generation2. analog electronics3. solid state switching circuits4. parallel circuits5. switchgear and protection6. op amp circuits7. transistor audio power amplifiers8. electrostatics9. heating and welding10. multi stage transistor amplifiers11. passive filters12. network theorems13. regulated d c power supply14. a c fundamentals circuits and circuit theory15. electromagnetic induction16. power electronics17. magnetism and electromagnetism18. transformers19. modulation and demodulation20. d c generators21. semiconductor theory22. single phase induction motors23. semiconductor diode24. hybrid parameters25. digital electronics26. oscillators27. earthing or grounding28. single stage transistor amplifiers29. d c motors30. transistor biasing31. amplifiers with negative feedback32. basic electrical33. electronic instruments34. synchronous motors35. field effect transistors fet36. magnetic circuit37. control systems38. industrial drives39. power generation40. series parallel circuits41. transistor tuned amplifiers42. electrical engineering materials43. rectifiers and converters44. integrated circuits45. scr silicon controlled rectifiers46. cables47. polyphase induction motors48. measurement and instrumentation49. transistors50. electrical machine design51. electrolysis and storage of batteries52. electric traction53. transmission and distribution
2301. Negative feedback is employed in __________________?
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A. Rectifiers

B. Amplifiers

C. None of the above

D. Oscillators

2302. An amplifier without feedback has a voltage gain of 50,input resistance os 1 K? & Output resistance of 2.5K?.The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback factor of 0.2 is___________?
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A. 5K?

B. 1/5K?

C. 11K?

D. 1/11K?
2303. An ideal OP-AMP is an ideal___________?
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A. voltage controlled current source

B. Voltage controlled voltage source

C. Current controlled voltage source

D. Current controlled Current source

2304. In a certain three-branch parallel circuit, R1 has 12 mA through it, R2 has 15 mA through it, and R3 has 25 mA through it. After measuring a total of 27 mA, you can say that____________?
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A. R2 is open

B. the circuit is operating properly

C. R3 is open

D. R1 is open

2305. A crystal diode utilises .. characteristic for rectification
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A. reverse

B. forward

C. none of the above

D. forward or reverse

2306. In a transistor ______________?
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A. IC = IE + IB

B. IE = IC + IB

C. IB = IC + IE

D. IE = IC IB

2307. The relation between and a is______________?
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A. = 1 / (1 a )

B. = a / (1 + a )

C. = (1 a ) / a

D. = a / (1 a )
2308. The values of h parameter of a transistor in CE arrangement are ____________ arrangement?
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A. None of the above

B. Different from that in CB

C. The same as for CC

D. The same as for CB

2309. Hybrid means_____________?
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A. None of the above

B. Unique

C. Mixed

D. Single

2310. In an electric room heat convector the method of heating used is______________?
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A. arc heating

B. dielectric heating

C. induction heating

D. resistance heating
2311. In an LC circuit, when the capacitor is maximum, the inductor energy is____________?
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A. Maximum

B. Half-way between maximum and minimum

C. Minimum

D. None of the above

2312. The power dissipation in each of four parallel branches is 1.2 W. The total power dissipation is________________?
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A. 4.8 W

B. 0.3 W

C. 1.2 W

D. 12 W

2313. The following currents are measured in the same direction in a three-branch parallel circuit: 200 mA, 340 mA, and 700 mA. The value of the current into the junction of these branches is____________?
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A. 200 mA

B. 900 mA

C. 540 mA

D. 1.24 A
2314. If there are a total of 120 mA into a parallel circuit consisting of three branches, and two of the branch currents are 40 mA and 10 mA, the third branch current is_________________?
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A. 120 mA

B. 40 mA

C. 50 mA

D. 70 mA
2315. The ripple factor of a half-wave rectifier is_________________?
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A. 0.48

B. 2.5

C. 2

D. 1.21

2316. The phase difference between the input and output voltages of a transistor connected in common emitter arrangement is___________?
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A. 90o

B. 270o

C. 0o

D. 180o
2317. In a domestic cake baking oven the temperature is controlled by________________?
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A. series-parallel operation

B. voltage variation

C. auto-transformer

D. thermostat

2318. The input impedance of a transistor connected in___________arrangement is the highest?
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A. none of the above

B. common base

C. common emitter

D. common collector
2319. The value of for a transistor is generally____________?
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A. less than 1

B. between 20 and 500

C. above 500

D. 1

2320. One condition for oscillation is_____________?
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A. A phase shift around the feedback loop of 0o

B. A gain around the feedback loop of one-third

C. A phase shift around the feedback loop of 180o

D. A gain around the feedback loop of less than 1

2321. A crystal diode has______________?
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A. three pn junctions

B. one pn junction

C. none of the above

D. two pn junctions

2322. Due to which of the following reasons it is desirable to have short arc length ?
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A. All of the above

B. To have better stirring action

C. To increase the life of roof refractory

D. To achieve better heating

E. To reduce problem of oxidation

2323. In resistance heating highest working temperature is obtained from heating elements made of_____________?
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A. silver

B. nichrome

C. nickel copper

D. silicon carbide
2324. In electric press, mica is used because it is _________ conductor of heat but/and __________ conductor of electricity?
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A. good, good

B. bad, bad

C. good, bad

D. bad, good

2325. When current feedback (negative) is applied to an amplifier, its input impedance _____________?
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A. Is increased

B. Remains the same

C. None of the above

D. Is decreased
2326. The emitter of a transistor is___________doped?
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A. lightly

B. heavily

C. none of the above

D. moderately

2327. In CE arrangement, the value of input impedance is approximately equal to ______________?
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A. Hre

B. None of the above

C. Hoe

D. Hie
2328. In order to determine hfe and hie parameters of a transistor, __________ is an a.c. short-circuited?
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A. Output

B. None of the above

C. Input as well as output

D. Input

2329. A perfect black body is one that_____________?
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A. absorbs, reflects and transmits all incident radiations

B. transmits all incident radiations

C. absorbs all incident radiations

D. reflects all incident radiations

2330. The reverse current in a diode is of the order of _____________?
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A. ?A

B. mA

C. A

D. kA

2331. The phase difference between the input and output voltages of a transistor connected in common collector arrangement is_____________?
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A. 2700

B. 1800

C. 00

D. 900

2332. A 741-Type OP-AMP has a gain-bandwith product of 1MHz. A non-inverting amplifier using this opamp & having a voltage gain of 20db will exhibit -3db bandwidth of______________?
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A. 50KHz

B. 1000/7.07KHz

C. 100KHz

D. 1000/17KHz

2333. In a npn transistor,_____________are the minority carriers?
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A. donor ions

B. holes

C. acceptor ions

D. free electrons

2334. If the arrow of crystal diode symbol is positive w.r.t. bar, then diode is _____________biased?
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A. either forward or reverse

B. none of the above

C. forward

D. reverse

2335. In induction heating ___________ is abnormally high?
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A. voltage

B. frequency

C. phase angle

D. current

2336. In a resistance furnace the atmosphere is_____________?
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A. neutral

B. oxidizing

C. reducing

D. deoxidising

2337. A half-wave rectifier has an input voltage of 240 V r.m.s. If the step-down transformer has a turns ratio of 8:1, what is the peak load voltage? Ignore diode drop?
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A. 86.5 V

B. 30 V

C. 27.5 V

D. 42.5 V
2338. Direct arc furnaces have which of the following power factors ?
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A. Low, leading

B. Unity

C. Any of the above

D. Low, lagging
2339. The power gain in a transistor connected in___________arrangement is the highest?
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A. common collector

B. common emitter

C. common base

D. none of the above

2340. Which of the following is an advantage of heating by electricity ?
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A. All of the above

B. Quicker operation

C. Higher efficiency

D. Absence of flue gases

2341. Which of the following will happen if the thickness of refractory wall of furnace is increased ?
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A. Heat loss through furnace wall will increase

B. Energy consumption will increase

C. Temperature inside the furnace will fall

D. Temperature on the outer surface of furnace walls will drop
2342. Mains a.c. power is converrted into d.c. power for_________________?
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A. none of the above

B. lighting purposes

C. using in electronic equipment

D. heaters

2343. The disadvantage of a half-wave rectifier is that the__________________?
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A. none of the above

B. output is difficult to filter

C. components are expensive

D. diodes must have a higher power rating

2344. Three 47 ? resistors are connected in parallel across a 110 volt source. The current drawn from the source is approximately_______________?
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A. 47 mA

B. 780 mA

C. 7.06 A

D. 2.3 A

2345. If the doping level of a crystal diode is increased, the breakdown voltage__________________?
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A. is decreased

B. none of the above

C. remains the same

D. is increased

2346. Properly of low temperature co-eflficient of heating element is desired due to which of the following reasons ?
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A. To avoid initial rush of current

B. To avoid change in kW rating with temperature

C. Both (A) and (B)

D. Either (A) or (B)

2347. If the crystal frequency changes with temperature, we say that crystal has___________temperature coefficient?
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A. Negative

B. None of the above

C. Zero

D. Positive
2348. Most of the majority carriers from the emitter____________?
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A. recombine in the emitter

B. recombine in the base

C. pass through the base region to the collector

D. none of the above

2349. Four resistors of equal value are connected in parallel. If the total voltage is 15 V and the total resistance is 600 ?, the current through each parallel resistor is____________?
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A. 6.25 mA

B. 25 mA

C. 100 mA

D. 200 mA

2350. The phase difference between the input and output voltages in a common base arrangement is___________?
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A. 0o

B. 90o

C. 180o

D. 270o