For cost and safety, the outdoor substations are installed for voltages above_________________?

A. Open circuit
B. Short-circuit
E. Long
D. None of the above

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

A. zero
B. infinity
C. unity
D. none of the above

A. burning
B. arcing
C. melting
D. none of the above

A. 100 microsecond
B. 50 millisecond
C. 0.5 sec
D. 0.1 sec

A. interrupting an electrical circuit
B. switching an electrical circuit 111.
C. switching and controlling an electrical circuit
D. switching, controlling and protecting the electrical circuit and equipment