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
5701. Which of the following motors one will choose to drive the rotary compressor ?
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A. Synchronous motor

B. Universal motor

C. D.C. series motor

D. D.C. shunt motor

5702. In which of the following applications D.C. series motor is invariably tried?
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A. Fan motor

B. Drive for a water pump

C. Motor operation in A.C. or D.C

D. Starter for a car
5703. The starting resistance of a D.C. motor is generally_______________?
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A. around 500 Q

B. low

C. 1000 Q

D. infinitely large

5704. If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens____________?
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A. this will make armature to take heavy current, possibly burning it

B. nothing will happen to motor

C. motor will come to stop

D. this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses

5705. Buses, trains, trolleys, hoists, cranes require high starting torque and therefore make use of_____________?
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A. D.C. series motor

B. all of above motors

C. D.C. shunt motor

D. induction motor

5706. If the load on a DC shunt motor is increases, its speed is slightly reduced due to______________?
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A. decrease in reactance

B. increase in armature current

C. decrease in back emf

D. increase in flux

5707. The plugging gives the____________?
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A. smallest torque braking

B. zero torque braking

C. none of the above

D. highest torque braking
5708. When the armature of a D.C. motor rotates, e.m.f. induced is___________?
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A. none of the above

B. back e.m.f

C. mutually induced e.m.f.

D. self-induced e.m.f.

5709. The armature voltage control of D.C. motor provides____________?
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A. constant voltage drive

B. none of the above

C. constant current drive

D. constant torque drive
5710. Which method of braking is generally used in elevators ?
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A. Rheostatic braking

B. Plugging

C. Regenerative braking

D. None of the above

5711. In D.C. motor which of the following can sustain the maximum temperature rise?
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A. Field winding

B. Slip rings

C. Commutator

D. Armature winding

5712. A three point starter is considered suitable for______________?
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A. shunt motors

B. shunt as well as compound motors

C. all D.C. motors

D. shunt, compound and series motors

5713. Usually wide and sensitive speed control is desired in case of____________?
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A. steel rolling mills

B. elevators

C. centrifugal pumps

D. colliery winders
5714. One D.C. motor drives another D.C. motor. The second D.C. motor when excited and driven_______________?
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A. also runs as a motor comes to stop after sometime

B. does not run as a generator

C. runs as a generator
5715. The stabilisation of operating point in potential divider method is provided by_______________?
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A. RC consideration

B. RE consideration

C. None of the above

D. VCC consideration

5716. A silicon transistor is biased with base resistor method. If =100, VBE =0.7 V, zero signal collector current IC = 1 mA and VCC = 6V , what is the value of the base resistor RB ?
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A. 530 kO

B. None of the above

C. 315 kO

D. 105 kO

5717. If biasing is not done in an amplifier circuit, it results in________________?
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A. Unfaithful amplification

B. None of the above

C. Decrease in the base current

D. Excessive collector bias

5718. For faithful amplification by a transistor circuit, the value of VCE should______________for silicon transistor?
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A. Be zero

B. Not fall below 1 V

C. None of the above

D. Be 0.2 V

5719. The value of VBE ___________________?
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A. None of the above

B. Is almost independent of IC

C. Is strongly dependant on IC

D. Depends upon IC to moderate extent

5720. For good stabilsation in voltage divider bias, the current I1 flowing through R1 and R2 should be equal to or greater than_____________?
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A. 10 IB

B. 3 IB

C. 4 IB

D. 2 IB

5721. The value of stability factor for a base resistor bias is________________?
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A. (+1)

B. (+1)RC

C. RB (+1)

D. 1-

5722. In a base resistor method, if the value of changes by 50, then collector current will change by a factor ___________________?
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A. 100

B. 50

C. 200

D. 25

5723. The leakage current in a silicon transistor is about_____________ the leakage current in a germanium transistor?
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A. One hundredth

B. One tenth

C. One thousandth

D. One millionth

5724. For proper amplification by a transistor circuit, the operating point should be located at the_____________ of the d.c. load line?
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A. The maximum current point

B. None of the above

C. Middle

D. The end point

5725. Operating point represents__________________?
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A. Zero signal values of IC and VCE

B. The magnitude of signal

C. Values of IC and VCE when signal is applied

D. None of the above

5726. In voltage divider bias, operating point is 3 V, 2 mA. If VCC = 9 V, RC = 2.2 kO, what is the value of RE ?
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A. 800 O

B. 1400 O

C. 1600 O

D. 2000 O

5727. The stability factor of a collector feedback bias circuit is_______________ that of base resistor bias?
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A. More than

B. None of the above

C. Less than

D. The same as

5728. Transistor biasing represents ______________ conditions?
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A. a.c

B. d.c

C. both a.c. and d.c

D. none of the above

5729. The disadvantage of base resistor method of transistor biasing is that it_________________?
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A. None of the above

B. Is sensitive to changes in

C. Is complicated

D. Provides high stability

5730. Thermal runaway occurs when_________________?
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A. Junction capacitance is high

B. Collector is reverse biased

C. Transistor is not biased

D. Emitter is forward biased

5731. If the maximum collector current due to signal alone is 3 mA, then zero signal collector current should be at least equal to___________________?
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A. 6 mA

B. 3 mA

C. mA

D. 1 mA

5732. In a transistor amplifier circuit VCE = VCB +________________?
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A. 5 VBE

B. 2VBE

C. None of the above

D. VBE
5733. In the design of a biasing circuit, the value of collector load RC is determined by__________________?
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A. VBE consideration

B. VCE consideration

C. None of the above

D. IB consideration

5734. An ideal value of stability factor is________________?
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A. 1

B. More than 200

C. 200

D. 100

5735. The point of intersection of d.c. and a.c. load lines represents __________________?
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A. Operating point

B. None of the above

C. Voltage gain

D. Current gain

5736. When the temperature changes, the operating point is shifted due to _______________?
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A. Change in the values of circuit resistance

B. Change in ICBO

C. Change in VCC

D. None of the above

5737. The operating point is also called the _______________?
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A. Cut off point

B. Saturation point

C. None of the above

D. Quiescent point
5738. The disadvantage of voltage divider bias is that it has _________________?
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A. Low base current

B. None of the above

C. Many resistors

D. High stability factor

5739. For faithful amplification by a transistor circuit, the value of VBE should_____________for a silicon transistor?
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A. Be zero

B. Not fall below 0.7 V

C. Be between 0 V and 0.1 V

D. Be 0.01 V

5740. If the temperature increases, the value of VCE_________________?
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A. Is decreased

B. Remains the same

C. Is increased

D. None of the above

5741. The zero signal IC is generally ______________ mA in the initial stages of a transistor amplifier?
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A. More than 10

B. 1

C. 3

D. 4

5742. The circuit that provides the best stabilization of operating point is___________________?
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A. Potential divider bias

B. Base resistor bias

C. None of the above

D. Collector feedback bias

5743. Transistor biasing is generally provided by a_______________?
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A. Biasing circuit

B. Bias battery

C. Diode

D. None of the above

5744. For proper operation of the transistor, its collector should have___________________?
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A. Proper forward bias

B. Very small size

C. Proper reverse bias

D. None of the above

5745. In a particular biasing circuit, the value of RE is about _________________?
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A. 10 kO

B. 800 O

C. 1 MO

D. 100 kO

5746. In voltage divider bias, VCC = 25 V; R1 = 10 kO; R2 = 2.2 V ; RC = 3.6 V and RE =1 kO. What is the emitter voltage?
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A. V

B. 8 V

C. 7 V

D. 3 V

5747. The purpose of resistance in the emitter circuit of a transistor amplifier is to _________________?
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A. Provide base-emitter bias

B. None of the above

C. Limit the maximum emitter current

D. Limit the change in emitter current
5748. The biasing circuit has a stability factor of 50. If due to temperature change, ICBO changes by 1 A, then IC will change by___________________?
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A. 20 A

B. 50 A

C. 25 A

D. 100 A

5749. Transistor biasing is done to keep _____________in the circuit?
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A. Proper alternating current

B. Collector current small

C. The base current small

D. Proper direct current
5750. The base resistor method is generally used in ________________?
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A. Rectifier circuits

B. Amplifier circuits

C. None of the above

D. Switching circuits