A thermal protection switch can protect against_____________?
A. short-circuit
B. temperature
C. overload
D. over voltage
Month: December 2018
SF6 gas______________?
SF6 gas______________?
A. is yellow in colour
B. is lighter than air
C. is nontoxic
D. has pungent small
E. none of the above
Which of the following medium is employed for extinction of arc in air circuit breaker?
Which of the following medium is employed for extinction of arc in air circuit breaker?
A. Water
B. Oil
C. Air
D. SF6
On which of the following routine tests are conducted ?
On which of the following routine tests are conducted ?
A. Oil circuit breakers
B. Air blast circuit breakers
C. Minimum oil circuit breakers
D. All of the above
The arcing contacts in a circuit breaker are made of______________?
The arcing contacts in a circuit breaker are made of______________?
A. copper tungsten alloy
B. porcelain
C. electrolytic copper
D. aluminium alloy
Arc in a circuit behaves as_______________?
Arc in a circuit behaves as_______________?
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
Fault diverters are basically____________?
Fault diverters are basically____________?
A. fuses
B. relays
C. fast switches
D. circuit breakers
Magnetic circuit breaker has ___________ trip action
Magnetic circuit breaker has ___________ trip action
A. delayed
B. instantaneous
C. both of the above
D. none of the above
Thermal circuit breaker has____________?
Thermal circuit breaker has____________?
A. delayed trip action
B. instantaneous trip action
C. both of the above
D. none of the above
With which of the following, a circuit breaker must be equipped for remote operation ?
With which of the following, a circuit breaker must be equipped for remote operation ?
A. Inverse time trip
B. Time-delay trip
C. Shunt trip
D. None of the above
E. All of the above