A. lengthening of the gap
B. cooling and blast effect
C. both A. and B
D. deionizing the oil with forced air
E. none of the above
Related Mcqs:
- The current zero interruption, in oil and air blast circuit breakers, is achieved by____________?
A. lengthening of the gap
B. cooling and blast effect
C. both (A) and (B)
D. deionizing the oil with forced air
E. none of the above - Air blast circuit breakers for 400 kV power system are designed to operate in_______________?
A. 100 microsecond
B. 50 millisecond
C. 0.5 sec
D. 0.1 sec - 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
E. any of the above - 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 - 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
E. any of the above - The time of closing the cycle, in modern circuit breakers is_____________?
A. 0.003 sec
B. 0.001 sec
C. 0.01 sec
D. 0.10 sec
E. none of the above - Insulation resistance of high voltage circuit breakers is more than________________?
A. 1 mega ohms
B. 10 mega ohms
C. 100 mega ohms
D. 500 mega ohms - Which of the following circuit breakers has high reliability and minimum maintenance ?
A. Air blast circuit breakers
B. Circuit breaker with SF6 gas
C. Vacuum circuit breakers
D. Oil circuit breakers - Air blast circuit breaker is used for_____________?
A. over currents
B. short duty
C. intermittant duty
D. repeated duty - Interruption of large currents by relay requires______________?
A. arc suppressing blow out coils
B. wide separation of the opened contacts
C. high speed opening of contacts
D. all of the above
