1. An isolator is a device design to operates on
(a) no load.
(b) normal condition.
(c) full load.
(d) none of the above. Answer
2. A circuit breaker is a device used to
(a) limit the current.
(b) interrupt the circuit.
(c) detect the fault current.
(d) control the fault current. Answer
3. In power system, the function of relay is to
(a) limit the current.
(b) control the fault current.
(c) detect the fault current.
(d) interrupt the circuit. Answer
4. The rating of a fuse is expressed in terms of
(a) Ampere.
(b) Volt.
(c) VAR.
(d) Watt. Answer
5. Which material is used in liquid fuses ?
(a) SF6.
(b) distilled water.
(c) carbon tetra chloride.
(d) transformer oil. Answer
6. The capacitor switching is easily done with
(a) oil circuit breaker.
(b) air blast circuit breaker.
(c) vacuum circuit breaker.
(d) any one of these. Answer
7. Which of the following relay is used for phase fault protection of short transmission lines ?
(a) Reactance relay.
(b) Impedance relay.
(c) mho relay.
(d) IDMT relay. Answer
8. Which of the following relay is used for phase fault protection of medium transmission lines ?
(a) Reactance relay.
(b) Impedance relay.
(c) mho relay.
(d) IDMT relay. Answer
9. Which of the following relay is used for phase fault protection of long transmission lines ?
(a) Reactance relay.
(b) Impedance relay.
(c) mho relay.
(d) IDMT relay. Answer
10. Directional relays work on the bases of flow of
(a) frequency.
(b) power.
(c) current.
(d) voltage wave. Answer
11. H.R.C. fuses provide best protection against
(a) overload.
(b) reverse current.
(c) open-circuits.
(d) short-circuits. Answer
12. Which of the following circuit breaker produce least arc energy?
(a) Air blast CB
(b) Air break CB.
(c) Minimum oil CB.
(d) Plain oil CB. Answer
13. In HRC Fuse, the fuse element is mainly made up of
(a) copper.
(b) aluminium.
(c) silver.
(d) lead tin alloy. Answer
14. A material best suited for manufacturing of fuse wire is
(a) Aluminium.
(b) Silver.
(c) Lead.
(d) Copper. Answer
15. The end caps used in HRC fuses are made by
(a) porcelain.
(b) brass.
(c) manganin.
(d) nichrome. Answer