A. maintain the arc
B. extinguish the arc
C. transmit large power
D. emit the ionizing electrons
A. power frequencies
B. higher frequencies entering generator or transformer units
C. either of the above
D. none of the above
A. 20 A
B. 50 A
C. 100 A
D. 200 A
A. resistance, reactance or impedance
B. voltage and current
C. light intensity
D. temperature
E. all above
A. Lightning arresters
B. Relays
C. Step-down transformer
D. Switchgear
A. required to operate the circuit breaker
B. absorbed by the circuit of relay
C. developed by the relay circuit
D. none of the above
A. overload
B. short-circuit and overload
C. open circuit, short-circuit and overload
D. none of the above