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
1351. Electrical power output in a D.C. generator is equal to_____________?
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A. Mechanical power input iron and friction losses copper losses

B. Electrical power developed in armature copper losses

C. Mechanical power input iron and friction losses

D. Electrical power developed in armature iron and copper losses

1352. Kirchhoff s law is applicable to____________?
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A. passive networks only

B. a.c. circuits only

C. d.c. circuits only

D. both a.c. as well d.c. circuits
1353. A synchronous motor is running on a load with normal excitation. Now if the load on the motor is increased
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A. power factor as well as armature current will decrease

B. power factor will increase but armature current will decrease

C. power factor will decrease and armature current will increase

D. power factor as well as armature current will increase

1354. If excitation of a synchronous motor running with a constant load is decreased from its normal value, ignoring effects of armature reaction, it leads to____________?
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A. increase in both armature current and power factor angle

B. increase in back e.m.f. but decrease in armature current

C. increase in both armature current and power factor which is lagging

D. increase in torque angle but decrease in back e.m.f.

1355. The maximum power developed in a synchronous motor occurs at a coupling angle of____________?
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A. 60

B. 30

C. 90

D. 180

1356. A pony motor is basically a_________?
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A. D.C. series motor

B. small induction motor

C. D.C. shunt motor

D. double winding A.C./D.C. motor

1357. A synchronous motor running with normal excitation adjusts to load increases essentially by increase in______________?
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A. back e.m.f.

B. torque angle

C. armature current

D. power factor

1358. A synchronous motor can develop synchronous torque:
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A. while over-excited

B. when under loaded

C. below or above synchronous speed

D. only at synchronous speed
1359. The percentage slip in case of a synchronous motor is____________?
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A. zero

B. 0.50%

C. 100%

D. 1%

1360. Which of the following is a bilateral element?
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A. Constant voltage source

B. None of the above

C. Constant current source

D. Capacitance
1361. The number of independent equations to solve a network is equal to_____________?
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A. the number of branches

B. sum of the number of branches and chords

C. sum of number of branches, chords and nodes

D. the number of chords
1362. Mostly, synchronous motors are of_____________?
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A. smooth cylindrical type machines

B. alternator type machines

C. salient pole type machines

D. induction type machines

1363. Salvage value of the plant is always____________?
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A. any of the above

B. negative

C. zero

D. positive

1364. Which of the following is the passive element?
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A. All of the above

B. Capacitance

C. Ideal current source

D. Ideal voltage source

1365. An over excited synchronous motor is used for____________?
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A. power factor corrections

B. variable speed loads

C. low torque loads

D. fluctuating loads

1366. Which of the following is not a method for estimating depreciation charges?
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A. Halseys 5050 formula

B. Straight line method

C. Diminishing value method

D. Sinking fund method

1367. If the field circuit of an unloaded salientpole synchronous motor gets suddenly open-circuited, then
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A. it runs at a slower speed

B. it continues to run at the same speed

C. the motor stops

D. it runs at a very high speed

1368. Which of the following source of power is least reliable?
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A. Wind power

B. iMHD

C. Geothermal power

D. Solar energy

1369. The concept on which Superposition theorem is based on_____________?
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A. non-linearity

B. duality

C. linearity

D. reciprocity

1370. In any linear bilateral network, if a source of e.m.f. E in any branch produces a current I in any other branch, then same e.m.f. acting in the second branch would produce the same current / in the first branch.
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A. superposition theorem

B. compensation theorem

C. above statement is associated with

D. none of the above

E. reciprocity theorem
1371. The size of a synchronous motor decreases with the increase in___________?
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A. speed

B. flux density

C. all of the above

D. horse power rating

1372. Which of the following motors will be used in electric clocks?
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A. D.C. series motor

B. D.C. shunt motor

C. A.C. induction motor

D. A.C. synchronous motor
1373. By which of the following methods the constant speed of a synchronous motor can be changed to new fixed value ?
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A. By interchanging any two phases

B. By changing the load

C. By changing the applied voltage

D. By changing the supply frequency
1374. The net armature voltage of a synchronous motor is equal to the_______________?
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A. arithmetic sum of Eb and V

B. arithmetic difference of Eb and V

C. vector difference of Eh and V

D. vector sum of Eb and V

1375. While calculating Rth in Thevenins theorem and Norton equivalent
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A. all voltage and current sources are made dead

B. all independent sources are made dead

C. only current sources are made dead

D. only voltage sources are made dead

1376. If in a synchronous motor, driving a given mechanical load and drawing current at a leading power factor from constant voltage supply its field excitation is increased, its power factor
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A. will become less

B. will remain unchanged

C. none of the above.

D. will become more

1377. Generating capacity connected to the bus bars and ready to take load when switched on is known as____________?
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A. firm power

B. cold reserve

C. spinning reserve

D. hot reserve

1378. In Thevenins theorem, to find Z
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A. all independent current sources are short circuited and independent voltage sources are open circuited

B. all independent voltage sources are open circuited and all independent current sources are short circuited

C. all independent voltage and current sources are short circuited

D. all independent voltage sources are short circuited and all independent current sources are open circuited
1379. Maximum power output is obtained from a network when the load resistance is equal to the output resistance of the network as seen from the terminals of the load. The above statement is associated with____________?
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A. Maximum power transfer theorem

B. Millmans theorem

C. Thevenins theorem

D. Superposition theorem

1380. Millmans theorem yields____________?
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A. equivalent voltage or current source

B. equivalent resistance

C. equivalent voltage source

D. equivalent impedance

1381. Which of the following is the disadvantage due to low power factor?
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A. Increased transmission losses

B. High cost of equipment for a given load

C. All of the above

D. Poor voltage regulation

1382. The double energy transient occur in the____________?
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A. purely inductive circuit

B. R-L circuit

C. R-L-C circuit

D. R-C circuit

1383. A sine wave has a frequency of 50 Hz. Its angular frequency is ________ radian/second.
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A. 25 JT

B. 5 n

C. 50 jt

D. 100 n
1384. While starting a salient pole synchronous motor by induction motor action and connecting field discharge resistance across field, starting and accelerating torque is produced by_____________?
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A. eddy current and hysteresis torque in pole faces

B. induction motor torque in field winding

C. reHetance motor torque due to saliency of the rotor

D. induction motor torque in damper winding

E. all of the above methods
1385. In whichof the following power plants the maintenance cost is usually high?
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A. Nuclear power plant

B. Hydro-electric power plants

C. Diesel engine power plants

D. Thermal power plants
1386. A linear resistor having 0 < R < o is a______________?
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A. current controlled resistor

B. voltage controlled resistor

C. both current controlled and voltage controlled resistor

D. none of the above

1387. In a load curve the highest point represents______________?
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A. none of the above

B. diversified demand

C. average demand

D. peak demand
1388. When the field of a synchronous motor is under-excited, the power factor will be____________?
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A. leading

B. lagging

C. unity

D. zero

1389. During load shedding:
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A. system voltage is reduced

B. system frequency is reduced Efficiency is the secondary consideration in

C. some loads are switched off

D. system power factor is changed

1390. The oscillations in a synchronous motor can be damped out by_______________?
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A. oscillations cannot be damped

B. running the motor on leading power factors

C. providing damper bars in the rotor pole faces

D. maintaining constant excitation

1391. A power transformer is usually rated in____________?
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A. kVAR

B. kVA

C. kW

D. kWh

1392. Which of the following should be used for extinguishing electrical fires?
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A. CO2 fire extinguisher

B. Carbon tetrachloride fire extinguisher

C. Foam type fire extinguisher

D. Water

1393. Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?
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A. Low short circuit ratio

B. Low field current

C. High core losses

D. High field current

1394. Direct conversion of heat into electrical energy is possible through____________?
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A. none of the above

B. fuel cells

C. solar cells

D. MHD generators
1395. Power factor of the following circuit will be unity
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A. inductance

B. capacitance

C. resistance

D. both A. and B.

1396. A network which contains one or more than one source of e.m.f. is known as___________?
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A. passive network

B. linear network

C. active network

D. non-linear network

1397. Kirchhoffs current law is applicable to only
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A. electric circuits

B. junction in a network

C. electronic circuits

D. closed loops in a network

1398. _____________can generate power at unpredictable or uncontrolled times?
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A. Any of the above

B. Solar power plant

C. Tidal power plant

D. Wind power plant

1399. The maximum power developed in a synchronous motor will depend on__________?
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A. the supply voltage only

B. the rotor excitation, supply voltage and maximum value of coupling angle (90)

C. the rotor excitation only

D. the rotor excitation and supply volt-age both

E. none of the above

1400. To determine the polarity of the voltage drop across a resistor, it is necessary to know___________?
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A. direction of current through the resistor

B. value of resistor

C. e.m.fs. in the circuit

D. value of current through the resistor