A. fuses
B. relays
C. fast switches
D. circuit breakers
Related Mcqs:
- To reduce short circuit fault currents are used_____________?
A. reactors
B. resistors
C. capacitors
D. none of the above - The inverse definite mean time relays are used for over current and earth fault protection of transformer against_________________?
A. heavy loads
B. internal short-circuits
C. external short-circuits
D. all of the above - relay is preferred for phase fault on short transmission line?
A. Induction type
B. Reactance
C. Impedance
D. None of the above - If the fault occurs near the impedance relay, the VII ratio will be____________?
A. constant for all distances
B. lower than that of if fault occurs away from the relay
C. higher than that of if fault occurs away from the relay
D. none of the above - The information to the circuit breaker under fault conditions is provided by____________?
A. relay
B. rewirable fuse
C. H.R.C. only
D. all of the above - On which of the following routine tests are conducted ?
A. Oil circuit breakers
B. Air blast circuit breakers
C. Minimum oil circuit breakers
D. All of the above - In order that current should flow without causing excessive heating or voltage drop, the relay contacts should_________________?
A. have low contact resistance
B. be clean and smooth
C. be of sufficient size and proper shape
D. have all above properties - Relays can be designed to respond to changes in________________?
A. resistance, reactance or impedance
B. voltage and current
C. light intensity
D. temperature
E. all above - Which of the following is the least expensive protection for overcurrent is low voltage system ?
A. Rewireable fuse
B. Isolator
C. Oil circuit breaker
D. Air break circuit breaker
E. None of the above - Bus coupler is very essential in arrangement______________?
A. single bus
B. double bus, double breaker
C. main and transfer bus
D. all of the above
