Interruption of large currents by relay requires______________?

Related Mcqs:

1. Admittance relay is __________ relay?

   A. impedance B. directional C. non-directional D. none of the above...

2. 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...

3. 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...

4. To reduce short circuit fault currents are used_____________?

   A. reactors B. resistors C. capacitors D. none of the above...

5. 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...

6. For which of the following protection from negative sequence currents is provided ?

   A. Generators B. Motors C. Transmission line D. Transformers...

7. 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...

8. 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...

9. The under voltage relay can be used for______________?

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

10. 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...