electrical engineering MCQs – Page 261

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 Review each marked answer and report any item that may be outdated or unclear.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
5201. A D.C. generator can be considered as____________?
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A. rotating amplifier

B. rectifier

C. primemover

D. power pump

5202. In D.C. generators, lap winding is used for______________?
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A. high voltage, low current

B. high voltage, high current

C. low voltage, low current

D. low voltage, high current
5203. In a separately excited generator supplying rated load the armature reaction.
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A. is always present

B. is always absent

C. may be sometimes present

D. none of the above

5204. Armature reaction in a generator results in_____________?
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A. damagnetising the center of all poles

B. magnetising the center of all poles

C. demagnetisation of leading pole tip and magnetisation of trailing pole tip

D. demagnetisation of trailing pole tip and magnetisation of leading pole tip

5205. Flemings right-hand rule regarding direction of induced e.m.f., correlates__________?
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A. magnetic flux, direction of force and direction of motion of conductor

B. magnetic field strength, induced voltage and current

C. magnetic flux, direction of motion and the direction of e.m.f. induced

D. magnetic flux, direction of current flow and resultant force

5206. For a D.C. machines laboratory following type of D.C. supply will be suitable___________?
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A. synchronous motor D.C. generator set

B. rotary converter

C. induction motor D.C. generator set

D. mercury are rectifier

5207. The main factor which leads to unstable parallel operation of flat and over compounded generators is_____________?
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A. unequal series field resistances

B. their rising voltage characteristics

C. unequal speed regulation of their primemovers

D. unequal number of turns in their series field windings

5208. The terminal voltage of a series generator is 150 V when the load current is 5 A. If the load current is increased to 10 A, the terminal voltage will be____________?
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A. none of the above

B. greater than 150 V

C. less than 150 V

D. 150 V

5209. Brushes of D.C. machines are made of_________?
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A. hard copper

B. all of above

C. soft copper

D. carbon
5210. A shunt generator running at 1000 r.p.m. has generated e.m.f. as 200 V. If the speed increases to 1200 r.p.m., the generated e.m.f. will be nearly_______________?
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A. 150 V

B. 240 V

C. 290 V

D. 175 V

5211. In case of D.C. machines, mechanical losses are primary function of____________?
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A. current

B. speed

C. voltage

D. none of above

5212. In a level compounded D.C. generator, full load terminal voltage is______________?
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A. equal to no-load terminal voltage

B. more than no-load terminal voltage

C. negligibly low

D. less than no-load terminal voltage

5213. In D.C. generators the polarity of the interpoles_____________?
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A. is opposite to that of the main pole ahead

B. is neutral as these poles do not play part in generating e.m.f.

C. is the same as that of the main pole ahead

D. is the same as that of the immediately preceding pole

5214. As a result of armature reaction, the reduction in the total mutual air gap flux in a D.C. generator is approximately______________?
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A. 25 percent

B. 40 percent

C. 5 percent

D. 10 percent

5215. Lap winding is composed of_____________?
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A. any even number of conductors

B. that even number which is exact multiple of poles

C. that even number which is exact multiple of poles + 2

D. any odd number of conductors

5216. Which of the following D.C. generators will be in a position to build up without any residual magnetism in the poles?
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A. Series generator

B. None of the above

C. Shunt generator

D. Compound generator

5217. To achieve sparkless commutation brushes of a D.C. generator are rockedm ahead so as to bring them?
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A. just behind the magnetic neutral axis

B. none

C. in magnetic neutral axis

D. just ahead of magnetic neutral axis
5218. A series generator can self-excite:______________?
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A. only if the load current is zero

B. none of the above

C. only if the load current is not zero

D. irrespective of the value of load current

5219. In a D.C. generator in case the resistance of the field winding is increased, then output voltage will____________?
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A. decrease

B. fluctuate heavily

C. remain unaffected

D. increase

5220. The essential condition for parallel operation of two D.C. generators is that they have ________________?
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A. the same drooping voltage characteristics

B. same kW rating

C. the same operation r.p.m.

D. same percentage regulation