Transmission and distribution mcq part -2

1. Which of the following is the source of heat generation in the cables ?
(a) Dielectric losses in cable insulation
(b) losses in the conductor
(c) Losses in the metallic sheathings and armourings
(d) All of the above

Ans: d

2. Due to which of the following reasons the cables should not be operated too hot ?
(a) The oil may loose its viscosity and it may start drawing off from higher levels
(b) Expansion of the oil may cause the sheath to burst
(c) Unequal expansion may create voids in the insulation which will lead to ionization
(d) The thermal instability may rise due to the rapid increase of dielectric losses with
temperature
(e) All of the above

Ans: e

3. Which of the following D.C. distribution system is the simplest and lowest in first cost
?
(a) Radial system
(b) Ring system
(c) Inter-connected system
(d) None of the above
Ans: a

4. A booster is a
(a) series wound generator
(b) shunt wound generator
(c) synchronous generator
(d) none of the above

Ans: a

5. Besides a method of trial and error, which of the following methods is employed for
solution of network problems in interconnected system ?
(a) Circulating current method
(b) Thevenin's theorem
(c) Superposition of currents
(d) Direct application of Kirehhoffs laws
(e) All of the above

Ans: e

6. Which of the following faults is most likely to occur in cables ?
(a) Cross or short-circuit fault
(b) Open circuit fault
(c) Breakdown of cable insulation
(d) All of the above

Ans: d

7. The cause of damage to the lead sheath of a cable is
(a) crystallisation of the lead through vibration
(b) chemical action on the lead when buried in the earth
(c) mechanical damage
(d) all of the above

Ans: d

8. The voltage of the single phase supply to residential consumers is
(a) 110 V
(b) 210 V
(c) 230 V
(d) 400 V

Ans: c

9. Most of the high voltage transmission lines in India are
(a) underground
(b) overhead
(c) either of the above
(d) none of the above

Ans: b

10. The distributors for residential areas are
(a) single phase
(b) three-phase three wire
(c) three-phase four wire
(d) none of the above

Ans: c

11. The conductors of the overhead lines are
(a) solid
(b) stranded
(c) both solid and stranded
(d) none of the above

Ans: b

12. High voltage transmission lines use
(a) suspension insulators
(b) pin insulators
(c) both (a) and (b)
(d) none of the above

Ans: a

13. Multicore cables generally use
(a) square conductors
(b) circular conductors
(c) rectangular conductors
(d) sector-shaped conductors
(e) none of the above

Ans: d

14. Distribution lines in India generally use
(a) wooden poles
(b) R.C.C. poles
(c) steel towers
(d) none of the above

Ans: b

15. The material commonly used for insulation in high voltage cables is
(a) lead
(b) paper
(c) rubber
(d) none of the above

Ans: b

16. The loads on distributors systems are generally
(a) balanced
(b) unbalanced
(c) either of the above
(d) none of the above

Ans: b

17. The power factor of industrial loads is generally
(a) unity
(b) lagging
(c) leading
(d) zero

Ans: b

18. Overhead lines generally use
(a) copper conductors
(b) all aluminium conductors
(c) A.C.S.R. conductors
(d) none of these

Ans: c

19. In transmission lines the cross-arms are made of
(a) copper
(b) wood
(c) R.C.C.
(d) steel

Ans: d

20. The material generally used for armour of high voltage cables is
(a) aluminium
(b) steel
(c) brass
(d) copper

Ans: b