Which of the following is the least expensive protection for overcurrent is low voltage system ?

Related Mcqs:

1. Over voltage protection is recommended for______________?

   A. hydro-electric generators B. steam turbine generators C. gas turbine generators D. all of the above E. none of the above...

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

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

3. For which of the following ratings of the transformer differential protection is recommended ?

   A. above 30 kVA. B. equal to and above 5 MVA C. equal to and above 25 MVA D. none of the above...

4. A thermal protection switch can protect against_____________?

   A. short-circuit B. temperature C. overload D. over voltage...

5. For the protection of power station buildings against direct strokes the requirements are___________?

   A. interception B. interception and conduction C. interception, conduction and dissipation D. interception, conduction, dissipation and reflection E. none of the above...

6. The delay fuses are used for the protection of ___________?

   A. motors B. power outlet circuits C. fluorescent lamps D. light circuits...

7. The inverse definite mean time relays are used for over current and earth fault protection of transformer against_________________?

   A. heavy loads B. internal short-circuits C. external short-circuits D. all of the above...

8. The single phasing relays are used for the protection of_____________?

   A. single phase motors only B. two phase motors only C. two single phase motors running in parallel D. three phase motors...

9. A fuse in a motor circuit provides protection against__________?

   A. overload B. short-circuit and overload C. open circuit, short-circuit and overload D. none of the above...

10. Protection by fuses is generally not used beyond__________?

    A. 20 A B. 50 A C. 100 A D. 200 A...