Transmission and distribution. Part – 3

21. Which distribution system is more reliable?

A. All are equally reliable

B. Tree system

C. Ring main system

D. Radial system

22. The booster is

A. Series wound D.C. Generator

B. Series inductor

C. Shunt capacitance

D. None of the above

23. In modeling the equivalent circuit of short length transmission line the line resistance and inductance are only considered because line capacitance to ground is

A. Equal to zero

B. Very small

C. Infinite

D. Very large

24. The insulators used in guy cables are

A. Egg or stay insulator

B. Shackle insulator

C. Pin type insulator

D. Disc type insulator

25. The inductance of 1-ф 2 wire line is given by D = distance between conductor, R = radius of conductor

A. 0.4 loge D/r mH/km

B. 0.55 loge D/r mH/km

C. 0.4 loge r/D mH/km

D. 0.55 loge r/D mH/km

26. Guy wire is employed for

A. Providing protection against surges

B. Proving emergency earth route

C. Support the pole

D. All of the above

27. Corona loss increase with

A. Decrease in conductor size & increase in supply frequency

B. Increase with conductor size & supply frequency

C. Decrease with conductor size & supply frequency

D. Increase with conductor size & decrease with frequency supply

28. Line trap in carrier current relating tuned to carrier frequency present

A. High impedance to carrier frequency but low impedance to power frequency

B. Low impedance to both power and carrier frequency

C. High impedance to both power and carrier frequency

D. Low impedance to carrier frequency but high imp to power frequency

29. Which one of the following grounding method is used to reduce the tower resistance where earth resistance is low?

A. Single driven rod

B. Multiple rods

C. Counter poises

D. Plats

30. Whenever the conductor are dead ended or there is a change in the direction of transmission line the insulator used

A. Pin type

B. Shackle type

C. Strain type

D. Disc type