electrical engineering MCQs – Page 11

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 Review each marked answer and report any item that may be outdated or unclear.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
201. If all the SCRs of 3 phase PAC is replaced by diodes, they would be triggered_____________?
comments icon0

A. 60 degree before the zero crossing of the corresponding line voltages

B. 60 degree after the zero crossing of the corresponding line voltages

C. 120 degree after the zero crossing of the corresponding line voltages

D. 120 degree before the zero crossing of the corresponding line voltages

202. The power transformer is a constant______________?
comments icon0
A. main flux device

B. power device

C. current device

D. voltage device

203. No-load current in a transformer________________?
comments icon0

A. leads the voltage by about 75

B. leads the voltage by about 15

C. lags behind the voltage by about 15

D. lags behind the voltage by about 75
204. If the supply frequency to the transformer is increased,the iron loss will__________?
comments icon0

A. not change

B. increase

C. any of the above

D. decrease

205. Advantages of Cuk converter is / are_____________?
comments icon0

A. Low stress on switch

B. None of these

C. Low stress on capacitor

D. Large number of reactive component

206. Which of the following material has nearly zero temperature co-efficient of resistance_________?
comments icon0
A. Manganin

B. Carbon

C. Copper

D. Porcelain

207. Three identical resistors are first connected in parallel and then in series. The resultant resistance of the first combination to the second will be_________________?
comments icon0

A. 3 times

B. 1/9 times

C. 1/3 times

D. 9 times

208. You have to replace 1500 Q resistor in radio. You have no 1500 Q resistor but have several 1000 Q ones which you would connect__________?
comments icon0

A. three in parallel

B. two in parallel

C. three in series

D. two in parallel and one in series
209. A full wave rectifier with resistive load produces___________?
comments icon0

A. Second harmonic

B. Fifth harmonic

C. Do not produce harmonics

D. Third harmonic

210. A TRIAC can be turned on with______________?
comments icon0

A. Negative voltage at the gate terminal

B. Positive voltage at the gate terminal

C. Either (a) or (b)

D. None of these

211. The maximum efficiency of a distribution transformer is____________?
comments icon0

A. at no load

B. at 50% full load

C. at full load

D. at 80% full load

212. Bidirectional semiconductor device is___________?
comments icon0

A. BJT

B. TRIAC

C. SCR

D. Diode

213. The noise resulting from vibrations of laminations set by magnetic forces, is termed as_________________?
comments icon0

A. magnetostrication

B. boo

C. hum

D. zoom

214. Transformer breaths in when_______________?
comments icon0

A. load remains constant

B. load on it decreases

C. load on it increases

D. none of the above

215. The phase angle of gate signal in TRIAC can be shifted by using_____________?
comments icon0

A. An inductor

B. Only (a) and (b)

C. A variable resistor

D. A capacitor

216. Whether circuit may be AC. or D. C. one, following is most effective in reducing the magnitude of the current?
comments icon0

A. Reactor

B. Inductor

C. Capacitor

D. Resistor
217. The dielectric strength of transformer oil is expected to be______________?
comments icon0

A. lkV

B. 33 kV

C. 330 kV

D. 100 kV

218. Which of the following properties is not necessarily desirable for the material for transformer core ?
comments icon0

A. High permeability

B. Low hysteresis loss

C. Adequate mechanical strength

D. High thermal conductivity
219. Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be_____________?
comments icon0
A. 10 ohms

B. 80 ohms

C. 20 ohms

D. 160 ohms

220. The magnetising current of a transformer is usually small because it has___________?
comments icon0
A. small air gap

B. laminated silicon steel core

C. fewer rotating parts

D. large leakage flux