A. current carrying contacts called electrodes
B. arc extinguishers
C. circuits to break the system
D. transformers to isolate the two systems
E. any of the above
0
Circuit breakers are essentially______________?
0
In order that current should flow without causing excessive heating or voltage drop, the relay contacts should_________________?
A. current carrying contacts called electrodes
B. arc extinguishers
C. circuits to break the system
D. transformers to isolate the two systems
E. any of the above
0
Thermal overload relays are used to protect the motor against over current due to____________?
A. have low contact resistance
B. be clean and smooth
C. be of sufficient size and proper shape
D. have all above properties
0
Overload relays are of_______________type
A. short-circuits
B. heavy loads
C. grounds
D. all of the above
0
A thermal protection switch can protect against_____________?
A. induction
B. solid state
C. thermal
D. electromagnetic
E. all above
0
SF6 gas______________?
A. short-circuit
B. temperature
C. overload
D. over voltage
0
Which of the following medium is employed for extinction of arc in air circuit breaker?
A. is yellow in colour
B. is lighter than air
C. is nontoxic
D. has pungent small
E. none of the above
0
On which of the following routine tests are conducted ?
A. Water
B. Oil
C. Air
D. SF6
0
The arcing contacts in a circuit breaker are made of______________?
A. Oil circuit breakers
B. Air blast circuit breakers
C. Minimum oil circuit breakers
D. All of the above
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