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
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
A. transmission line
B. motor
C. generator
D. feeder
A. Air blast circuit breakers
B. Circuit breaker with SF6 gas
C. Vacuum circuit breakers
D. Oil circuit breakers
A. short transmission line
B. medium transmission line
C. long transmission line
D. medium and long transmission lines
A. to operate the relay of circuit breaker
B. as a substitute for circuit breaker
C. always independent of the position of circuit breaker
D. generally on both sides of a circuit breaker
A. over currents
B. short duty
C. intermittant duty
D. repeated duty
A. have low contact resistance
B. be clean and smooth
C. be of sufficient size and proper shape
D. have all above properties