electrical engineering MCQs – Page 6

Practise multiple-choice questions from electrical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

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
101. Thyristor can be protected from over voltages by using____________?
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A. heat sink.

B. snubber circuit.

C. voltage clamping device.

D. fuse.

102. SCR will be turned off when anode current is_______________?
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A. < latching current but greater than holding current and gate signal is 0.

B. less than holding current.

C. < latching current but greater than holding current and gate signal is present.

D. both (A) and (B).
103. Which statement is true for latching current ___________?
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A. t is related to turn off process of the device.

B. It is related to conduction process of device.

C. It is related to turn on process of the device.

D. Both C and D.

104. Which of following is not a power transistor?
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A. COOLMOS

B. IGBTs

C. SITS

D. TRIAC
105. In a three phase converter, the number of notches per cycle is____________?
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A. Nine

B. Three

C. Six

D. One

106. What is used to protect a thyristor from high di / dt conditions__________?
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A. Inductor

B. Fuse.

C. Voltage clamping device

D. Snubber circuit

107. By which one of the following we can measure the reliability of a string_____________?
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A. Factor of safety

B. String efficient

C. Reliability factor

D. Derating factor
108. In radiative coupling, the emitter radiation field_____________?
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A. Decays as R, where R is the separation distance between the emitter and the receptor

B. Decays as 1 / R, where R is the separation distance between the emitter and the receptor

C. Decays as 1 / 2 R, where R is the separation distance between the emitter and the receptor

D. Decays as 2R, where R is the separation distance between the emitter and the receptor

109. For bidirectional operation of converters____________?
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A. A series combination of controllable switch and a diode is used

B. A series combination of controllable switch and a capacitor is used

C. A parallel combination of controllable switch and capacitor is used

D. A parallel combination of controllable switch and a diode is used
110. If the anode current is 800 A, then the amount of current required to turn off the GTO is about____________?
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A. 600 A

B. 20 A

C. 400 A

D. 200 A
111. With increase in firing angle,
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A. Both harmonic distortion and quality of input current increases

B. Harmonic distortion increases and quality of input current decreases

C. Harmonic distortion decreases and quality of input current increases

D. Both harmonic distortion and quality of input current decreases

112. In rectifiers, load current flow is_________?
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A. Non directional

B. Bidirectional

C. Either (a) or (b)

D. Unidirectional
113. During gate recovery time_____________?
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A. charge carriers of J2 junction recombined

B. charge carriers of J2 junction is swept out

C. charge carrier of J1 junction removed

D. charge carriers of J3 junction is removed

114. Double edge modulation eliminates certain harmonics when the reference is a__________?
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A. Trapezoidal wave

B. Triangular wave

C. Square wave

D. Sine wave
115. Which of the following has no units?
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A. ermittivity

B. Moment of a magnet

C. Permeability

D. Magnetic susceptibility
116. Which of the following are the passive elements?
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A. Bulb

B. None of these.

C. Resistor

D. Both
117. In ac dc conversion, when the switch is closed then the sum of voltages around the loop is____________?
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A. Non zero

B. Equal to the sum of voltage when switch is open

C. Zero

D. Twice of the voltage when switch is open

118. A silicon controlled racitifier (SCR) is a ____________?
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A. Device with four junction

B. None of the above

C. Unijunction device

D. Device with three junction
119. Thermal voltage VT can be given by____________?
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A. KT/q

B. Kq/T

C. (K2/q)(T + 1/T 1)

D. qT/K

120. Between the incoming and outgoing devices in voltage commutation
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A. No overlapping operation

B. None of these

C. Small overlapping operation

D. Large overlapping takes place