A. arc suppressing blow out coils
B. wide separation of the opened contacts
C. high speed opening of contacts
D. all of the above
Related Mcqs:
- Admittance relay is __________ relay?
A. impedance
B. directional
C. non-directional
D. none of the above - The current zero interruption, in oil and air blast circuit breakers, is achieved by_______________?
A. lengthening of the gap
B. cooling and blast effect
C. both A. and B
D. deionizing the oil with forced air
E. none of the above - The current zero interruption, in oil and air blast circuit breakers, is achieved by____________?
A. lengthening of the gap
B. cooling and blast effect
C. both (A) and (B)
D. deionizing the oil with forced air
E. none of the above - To reduce short circuit fault currents are used_____________?
A. reactors
B. resistors
C. capacitors
D. none of the above - Short-circuit currents are due to_______________?
A. single phase to ground faults
B. phase to phase faults
C. two phase to ground faults
D. three phase faults
E. any of these - For which of the following protection from negative sequence currents is provided ?
A. Generators
B. Motors
C. Transmission line
D. Transformers - The relay operating speed depends upon_________________?
A. the spring tension
B. the rate of flux built up
C. armature core air gap
D. all of the above - Overheating of relay contacts or contact born out is due to_______________?
A. slow making and breaking of load circuit contacts
B. foreign matter on the contact surface
C. too low contact pressure
D. all of the above - The under voltage relay can be used for______________?
A. generators
B. busbars
C. transformers
D. motors
E. all of the above - The torque produced in induction type relay (shaded pole structure) is_____________?
A. inversely proportional to the current
B. inversely proportional to the square of the current
C. proportional to the current
D. proportional to square of the current
