Transmission and distribution. Part – 5

41. The leakage current must not be more than ____ of maximum supply current.

A. 1/1000

B. 1/100

C. 1/5000

D. 1/500

42. Which of the following regulation is consider to be the best?

A. 3%

B. 10%

C. 80%      

D. 96%

43. The most commonly used material for insulators of overhead lines is

A. Porcelain

B. Glass

C. Steatite

D. None of the above

44. Sag is provided in overhead lines so that

A. Safe tension is not exceeded

B. Repair can be made

C. Conductor material is saved

D. None of the above

45. By increasing the clearance spacing between the phases of the transmission lines corona discharge effect

A. Increases

B. Reduces

C. Remains the same

D. None of the above

46. In a D.C. 2-wire feeder, the voltage drop per wire is 2.5%, the transmission efficiency of feeder

A. 97.50%

B. 95%

C. 93.75%

D. 98.75%

47. To increase the capacity of a transmission line for transmitting power which of the following must be decreased?

A. Capacitance

B. Line inductance

C. Voltage

D. All of the above

48. As a matter of economy, voltage for power transmission should be

A. Low

B. Medium

C. High

D. None of the above

49. Which of the distribution system is used for balanced loads?

A. 1-phase, 3-wires system

B. 3-phase, 4-wire system

C. 3-phase, 3-wire system

D. None of the above

50. If 3 MW power is to be transmitted over a distance of 30 km. The desirable transmission voltage will be

A. 11KV

B. 33KV

C. 66KV

D. 3.3KV