electrical engineering MCQs – Page 8

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 Review each marked answer and report any item that may be outdated or unclear.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
141. A single phase one pulse controlled circuit has a resistance R and counter emf E load 400 sin(314 t) as the source voltage. For a load counter emf of 200 V, the range of firing angle control is _____?
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A. 60 to 120.

B. 60 to 180.

C. 30 to 150.

D. 30 to 180.

142. Dynamic equalising circuit is useful____________?
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A. To limit di / dt of SCR

B. To limit dV / dt of SCR

C. For voltage equalisation

D. Both B and C
143. The man made noise sources is / are_____________?
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A. Switches, radio interferences

B. All of these

C. Computers, digital electronics

D. Motors

144. Choppers is a_______________?
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A. DC AC converters

B. DC DC converters

C. AC AC converters

D. AC DC converters

145. A Triac has three terminals viz ___________?
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A. Two main terminal and a gate terminal

B. None of the above

C. Cathode, anode, gate

D. Drain, source, gate

146. COOLMOS device can be used in application up to power range of___________?
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A. 500 VA

B. 2 KVA

C. 1 KVA

D. 100 KVA

147. Unipolar modulation is generally used in____________?
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A. AC AC converters

B. DC AC converters

C. DC DC converters

D. AC DC converters

148. Inductor does not allow the sudden change of
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A. None of the above

B. voltage

C. power

D. current
149. ON state voltage drop across SCR lie between the range_____________?
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A. 0 0.5 V.

B. 0.5 1 V.

C. 1.5 2 V.

D. 1 1.5 V.
150. Let of a thyristor Vc1, Vc2, Vc3 are forward break over voltage for gate current Ig1, Ig2, Ig3 respectively. Then________________?
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A. Vc1 > Vc2 > Vc3 when Ig1 > Ig2 > Ig3.

B. Vc1 > Vc2 > Vc3 when Ig1 < Ig2 < Ig3.

C. Vc1 = Vc2 = Vc3 any value of Ig.

D. Vc1 > Vc2 > Vc3 when Ig1 aYEN Ig2 &Atil

151. In bipolar modulation, the carrier is symmetric about zero with amplitude equal to Cm, the PWM output
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A. Switches between 1 / 2 and + 1 / 2

B. Zero

C. Switches between 0 and + 1

D. Switches between 1 and + 1

152. The conduction losses in IGBT is____________?
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A. Equal to that of MOSFET

B. Equal to that of BJT

C. More than that of MOSFET

D. Lower than that of MOSFET
153. DIAC are specifically designed to trigger______________?
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A. SCR

B. Only (a) and (b)

C. GTO

D. TRIAC

154. Example of a voltage clamping device______________?
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A. metal oxide varistor

B. snubber circuit

C. fast acting fuse

D. aluminium block

155. Which following is a two terminal three layer device?
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A. BJT

B. None of above

C. Power dioed

D. MOSFET

156. In a silicon controlled rectifier, the load is connected___________?
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A. In series with cathode

B. In series with anode

C. Across cathode

D. Across anode

157. In BJT, switching losses occurs___________?
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A. Only at turn on

B. Only at turn off

C. Both at turn on and off

D. None of these

158. The maximum di/dt in a SCR is____________?
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A. Directly proportional to supply voltage

B. Directly proportional to inductance in the circuit

C. Inversely proportional to supply voltage

D. Both A and B
159. The square wave operation of 3 phase VSI lines contains the harmonics. The amplitudes are____________?
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A. Directly proportional to their harmonic order

B. None of these

C. Inversely proportional to their harmonic order

D. Not related to their harmonic order

160. A thyristor equivalent of a thyratron tube is a _________?
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A. Silicon controlled-rectifier SCR

B. None of above

C. Diac

D. Triac