A. Current transformer
B. Voltage transformer
C. Power transformer
D. Step down transformer
Answer: A. Current transformer
Explanation:
If the current transformer secondary is not shorted when unused and kept open then it can develop a very high voltage across secondary which may damage transformer insulation.
More MCQS With Fully Explained
1. Under over excitation synchronous phase modifier works as
2. The neutral of the power system may be connected to earth
3. The time to open the circuit breaker contact is called as
4. A 100 Ah capacity battery should deliver a current of 10 A for approximately _____ hrs.
5. For 400KV line, The Spacing Between phase conductor is around
6. Shunt capacitors in a sub-station
7. An alternator is said to be over excited when it is operating at
8. In case of transformer Buchholz relay is used to protect from
9. Series capacitors are used to
10. Disadvantage of low power factor is
11. The colour of neutral three core flexible cable is
12. The location of ground faults in underground cables can be found by
13. Fault location in an HV cable is done by
15. Which of the following is not a valid advantage of bundle conductor?
16. Star-star power transformer is protected by current transformer having
17. The surge resistance of cables is
18. Skin effect is only noticeable at _______ frequencies.
19. When transmission voltage is increased, the line losses are
20. Var compensators are used to
21. High voltage transmission lines use
22. The material used for insulators are
24. Isolator in sub station is open under ------------- condition?
38. A thermal protection relay provides protection against what?
39. Mho relays are used for the protection of which of the following lines?
40. The rate of rise of re-striking voltage is dependent upon
41. If sag in an overhead line increase, tension in the line