The voltage appearing across the contacts after opening of the circuit breaker is called__________voltage

A. recovery
B. surge
C. operating
D. arc

Large internal faults are protected by_______________?

A. merz price percentage differential protection
B. mho and ohm relays
C. horn gaps and temperature relays
D. earth fault and positive sequence relays

Directional relays are based on flow of____________?

A. power
B. current
C. voltage wave
D. all of the above

Air blast circuit breaker is used for_____________?

A. over currents
B. short duty
C. intermittant duty
D. repeated duty

Circuit breakers usually operate under______________?

A. transient state of short-circuit current
B. sub-transient state of short-circuit current
C. steady state of short-circuit current
D. after d.c. component has ceased

D.C. shunt relays are made of_____________?

A. few turns of thin wire
B. few turns of thick wire
C. many turns of thin wire
D. many turns of thick wire

Circuit breakers are essentially____________?

A. current carrying contacts called electrodes
B. arc extinguishers
C. circuits to break the system
D. transformers to isolate the two systems

Circuit breakers are essentially______________?

A. current carrying contacts called electrodes
B. arc extinguishers
C. circuits to break the system
D. transformers to isolate the two systems

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

Thermal overload relays are used to protect the motor against over current due to____________?

A. short-circuits
B. heavy loads
C. grounds
D. all of the above