Category: Switchgear and Protection

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

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

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

A. delayed
B. instantaneous
C. both of the above
D. none of the above

A. arc suppressing blow out coils
B. wide separation of the opened contacts
C. high speed opening of contacts
D. all of the above

A. a capackive reactance
B. an inductive reactance
C. a resistance increasing with voltage rise across the arc
D. a resistance decreasing with voltage rise across the arc

A. relay
B. rewirable fuse
C. H.R.C. only
D. all of the above

A. generators
B. busbars
C. transformers
D. motors
E. all of the above

A. Lightning arrestors are used before the switchgear
B. Shunt reactors are used as compensation reactors
C. The peak short current is (1.8 xV2) times the A.C. component
D. The MVA at fault is equal to base MVA divided by per unit equivalent fault reactance

A. protect the line
B. open the circuit
C. protect the appliance
D. prevent excessive currents
E. none of the above