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
7301. Which of the following distribution systems is more reliable?
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A. All are equally reliable

B. Ring main system

C. Radial system

D. Tree system

7302. A circuit is disconnected by isolators when____________?
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A. line is on full load

B. line is energized

C. circuit breaker is not open

D. there is no current in the line
7303. The angular displacement between two interconnected stations is mainly due to___________?
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A. armature reactance of both alternators

B. reactance of the interconnector

C. synchronous reactance of both the alternators

D. all of the above

7304. Which of the following equipment, for regulating the voltage in distribution feeder, will be most economical?
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A. Static condenser

B. Booster transformer

C. Synchronous condenser

D. Tap changing transformer

7305. The current drawn by the line due to corona losses is___________?
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A. square

B. sinusoidal

C. triangular

D. non-sinusoidal
7306. Overhead lines generally use__________________?
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A. all aluminium conductors

B. A.C.S.R. conductors

C. copper conductors

D. none of these

7307. The material commonly used for insulation in high voltage cables is_______________?
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A. paper

B. rubber

C. lead

D. none of the above

7308. The material commonly used for sheaths of underground cables is______________?
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A. rubber

B. iron

C. copper

D. lead
7309. If variable part of annual cost on account of interest and depreciation on the capital outlay is equal to the annual cost of electrical energy wasted in the conductors, the total annual cost will be minimum and the corresponding size of conductor will be most economical. This statement is known as___________________?
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A. Ohms law

B. Faradays law

C. Kelvins law

D. Kirchhoffs law

E. none of the above

7310. _______________are the conductors, which connect the consumers terminals to the distribution?
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A. Distributors

B. Service mains

C. Feeders

D. None of the above

7311. For an overhead line, the surge impedance is taken as________________?
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A. 20-30 ohms

B. 7080 ohms

C. none of the above

D. 5001000 ohms

E. 100200 ohms
7312. Which of the following is the demerit of a constant voltage transmission system ?
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A. Possibility of carrying increased power for a given conductor size in case of long-distance heavy power transmission

B. Increase of short-circuit current of the system

C. Availability of steady voltage at all loads at the line terminals

D. Improvement of power factor at times of moderate and heavy loads

E. Possibility of better protection for the line due to possible use of higher terminal reactants

7313. Which of the following is usually not the generating voltage ?
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A. 13.2 kV

B. 11 kV

C. 8.8 kV

D. 6.6 kV

7314. Which of the following characteristics should the line supports for transmission lines possess?
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A. All of the above

B. High mechanical strength

C. Low cost

D. Longer life

7315. When the interconnector between two stations has large reactance?
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A. none of the above

B. the transfer of power will take place with voltage fluctuation and noise

C. the stations will fall out of step because of large angular displacement between the stations

D. the transfer of power will take place with least loss

7316. Which of the following is not a constituent for making porcelain insulators ?
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A. Kaolin

B. Quartz

C. Felspar

D. Silica
7317. The minimum clearance between the ground and a 220 kV line is about_________________?
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A. 4.3 m

B. 10.5 m

C. 5.5 m

D. 7.0 m
7318. As compared to a 2-wire D.C. distributor, a 3-wire distributor with same maximum voltage to earth uses only__________________?
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A. 31.25 percent of copper

B. 66.7 percent of copper

C. 125 percent of copper

D. 33.3 percent of copper

7319. In the analysis of which of the following lines shunt capacitance is neglected?
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A. Medium as well as long transmission lines

B. Short transmission lines

C. Long transmission lines

D. Medium transmission lines

7320. Which of the following methods is used for laying of underground cables ?
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A. Solid system

B. All of the above

C. Draw-in-system

D. Direct laying

7321. The skin effect of a conductor will reduce as the__________?
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A. permeability of conductor material increases

B. diameter increases

C. resistivity of conductor material increases

D. frequency increases

7322. For aluminium, as compared to copper, all the following factors have higher values except:
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A. electrical conductivity

B. specific volume

C. resistance per unit length for same cross-section

D. co-efficient of linear expansion

7323. By which of the following methods string efficiency can be improved?
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A. None of the above

B. Using a guard ring

C. Using long cross arm

D. Grading the insulator

E. Any of the above
7324. Besides a method of trial and error, which of the following methods is employed for solution of network problems in interconnected system ?
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A. Circulating current method

B. Thevenins theorem

C. All of the above

D. Superposition of currents

E. Direct application of Kirehhoffs laws

7325. Pin type insulators are generally not used for voltages beyond_________?
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A. 22 kV

B. 33 kV

C. 1 kV

D. 11 kV

7326. The loads on distributors systems are generally__________________?
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A. none of the above

B. either of the above

C. unbalanced

D. balanced

7327. The operating voltage of high voltage cables is up to_______________?
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A. llkV

B. 6.6kV

C. 3.3kV

D. l.lkV

7328. In AC.S.R. conductors, the insulation between aluminium and steel conductors is_________?
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A. no insulation is required

B. varnish

C. bitumen

D. insulin

7329. The frequency of voltage generated, in case of generators, can be increased by___________?
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A. using reactors

B. none of the above

C. reducing the terminal voltage

D. adjusting the governor

E. increasing the load

7330. The voltage drop, for constant voltage transmission is compensated by installing__________?
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A. capacitors

B. synchronous motors

C. all of above

D. inductors

E. none of the above

7331. When a live conductor of public electric supply breaks down and touches the earth which of the following will happen?
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A. None of the above

B. Supply voltage will increase

C. No current will flow in the conductor

D. Current will flow to earth

E. Supply voltage will drop

7332. High voltage transmission lines use__________________?
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A. suspension insulators

B. pin insulators

C. both A. and B.

D. none of the above

7333. On which of the following factors skin effect depends?
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A. Resistivity of the conductor material

B. All of the above

C. Size of the conductor

D. Frequency of the current

7334. The steel used in steel cored conductors is usually__________?
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A. mild steel

B. alloy steel

C. stainless steel

D. all of the above

E. high speed steel

7335. The operating voltage of extra high tension cables is upto_______________?
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A. 33 kV

B. 66 kV

C. 6.6 kV

D. 11 kV

E. 132 kV

7336. The spacing between phase conductors of a 220 kV line is approximately equal to________________?
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A. 8.5 m

B. 2 m

C. 6 m

D. 3.5 m

7337. A uniformly-loaded D.C. distributor is fed at both ends with equal voltages. As compared to a similar distributor fed at one end only, the drop at the middle point is______________?
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A. one-third

B. one-half

C. none of the above

D. twice

E. one-fourth
7338. The distributors for residential areas are______________?
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A. three-phase three wire

B. single phase

C. three-phase four wire

D. none of the above

7339. For transmission of power over a distance of 200 km, the transmission voltage should be_________kv?
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A. 132 kV

B. 11 kV

C. 33 kV

D. 66 kV

7340. When a conductor carries more current on the surface as compared to core, it is due to___________?
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A. corona

B. permeability variation

C. skin effect

D. none of the above

E. unsymmetrical fault

7341. For which of the following equipment current rating is not necessary?
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A. Circuit breakers

B. Isolators

C. Load break switch

D. Circuit breakers and load break switches

7342. A 3-phase 4 wire system is commonly used on________________?
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A. secondary distribution

B. secondary transmission

C. primary distribution

D. primary transmission

7343. In transmission lines the cross-arms are made of________________?
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A. wood

B. copper

C. R.C.C.

D. steel
7344. Constant voltage transmission entails the following disadvantage?
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A. large conductor area is required for same power transmission

B. none of the above

C. short-circuit current of the system is increased

D. either of the above

7345. The presence of ozone due to corona is harmful because it________________?
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A. none of the above

B. transfer energy to the ground

C. gives odour

D. corrodes the material

E. reduces power factor

7346. In a tap changing transformer, the tappings are provided on__________?
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A. primary winding

B. any of the above

C. secondary winding

D. high voltage winding
7347. When an alternator connected to the bus-bar is shut down the bus-bar voltage will___________?
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A. none of the above

B. rise

C. fall

D. remain unchanged
7348. The wooden poles well impregnated with creosite oil or any preservative compound have life_____________?
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A. from 2 to 5 years

B. 60 to 70 years

C. 25 to 30 years

D. 10 to 15 years

7349. jCorona usually occurs when the electrostatic stress in air around the conductor exceeds?
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A. 22 kV (maximum value)/cm

B. 6.6 kV (r.m.s. value)/cm

C. 30 kV (maximum value)/cm

D. 11 kV (r.m.s. value)/cm

7350. A booster is a_________________?
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A. series wound generator

B. shunt wound generator

C. synchronous generator

D. none of the above