MCQOPTIONS
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MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
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 |
| Answer» C. open circuit, short-circuit and overload | |
| 2. |
In order that current should flow without causing excessive heating or voltage drop, the relay contacts should |
| A. | Have low contact resistance |
| B. | Be clean and smooth |
| C. | Be of sufficient size and proper shape |
| D. | Have all above properties |
| Answer» E. | |
| 3. |
What will be the reflection co-efficient of the wave of load connected to transmission line if surge impedance of the line is equal to load ? |
| A. | Zero |
| B. | Unity |
| C. | Infinity |
| D. | None of the above |
| Answer» B. Unity | |
| 4. |
Admittance relay is _______ relay. |
| A. | impedance |
| B. | directional |
| C. | non-directional |
| D. | none of the above |
| Answer» C. non-directional | |
| 5. |
Resistance grounding is used for voltage between |
| A. | 33kV to 66kV |
| B. | 22kV to 33kV |
| C. | 3.3kV and llkV |
| D. | none of the above |
| Answer» D. none of the above | |
| 6. |
When a wave propagates on a transmission line, it suffers reflection several times at |
| A. | tapping |
| B. | load end |
| C. | sending end |
| D. | sending and other end |
| E. | all of the above |
| Answer» E. all of the above | |
| 7. |
The short circuit in any winding of the transformer is the result of |
| A. | mechanical vibration |
| B. | insulation failure |
| C. | loose connection |
| D. | impulse voltage |
| Answer» E. | |
| 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 |
| Answer» E. | |
| 9. |
In a single bus-bar system there will be complete shut down when |
| A. | fault occurs on the bus itself |
| B. | fault occurs on neutral line |
| C. | two or more faults occur simultaneously |
| D. | fault occurs with respect to earthing |
| Answer» B. fault occurs on neutral line | |
| 10. |
To protect most of the electrical equipment handling low power, the types of relays used are |
| A. | Thermocouple |
| B. | Electronic and bimetallic |
| C. | Both (A) and (B) |
| D. | None of the above |
| Answer» D. None of the above | |
| 11. |
The inductive interference between power and communication line can be minimized by |
| A. | transposition of the power line |
| B. | transposition of the communication line |
| C. | both (A) and (B) |
| D. | increasing the distance between the conductors |
| Answer» D. increasing the distance between the conductors | |
| 12. |
The under voltage relay can be used for |
| A. | generators |
| B. | busbars |
| C. | transformers |
| D. | motors |
| E. | all of the above |
| Answer» F. | |
| 13. |
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 |
| Answer» C. proportional to the current | |
| 14. |
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 |
| Answer» F. | |
| 15. |
For which of the following ratings of the transformer differential protection is recommended ? |
| A. | above 30 kV |
| B. | equal to and above 5 MVA |
| C. | equal to and above 25 MVA |
| D. | none of the above |
| Answer» C. equal to and above 25 MVA | |
| 16. |
Large internal faults are protected by |
| A. | merz price percentage differential protection |
| B. | mho and ohm relays |
| C. | horn gaps and temperature relays |
| D. | earth fault and positive sequence relays |
| Answer» B. mho and ohm relays | |
| 17. |
The power loss is an important factor for the design of |
| A. | transmission line |
| B. | motor |
| C. | generator |
| D. | feeder |
| Answer» B. motor | |
| 18. |
The information to the circuit breaker under fault conditions is provided by |
| A. | relay |
| B. | rewirable fuse |
| C. | H.R.'only |
| D. | all of the above |
| Answer» B. rewirable fuse | |
| 19. |
The relay with inverse time characteristic will operate within |
| A. | 1.5 sec |
| B. | 5 to 10 sec |
| C. | 5 to 20 sec |
| D. | 20 to 30 sec |
| E. | none of the above |
| Answer» C. 5 to 20 sec | |
| 20. |
Which of the following is the least expensive protection for overcurrent is low voltage system ? |
| A. | Rewireable fuse |
| B. | Isolator |
| C. | Oil circuit breaker |
| D. | Air break circuit breaker |
| E. | None of the above |
| Answer» B. Isolator | |
| 21. |
Which of the following devices will receive voltage surge first travelling on the transmission line ? |
| A. | Lightning arresters |
| B. | Relays |
| C. | Step-down transformer |
| D. | Switchgear |
| Answer» B. Relays | |
| 22. |
A transmission line is protected by |
| A. | Inrush protection |
| B. | Distance protection |
| C. | Time graded and current graded over current protection |
| D. | Both (B) and (C) |
| Answer» E. | |
| 23. |
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 |
| Answer» D. interception, conduction, dissipation and reflection | |
| 24. |
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 |
| Answer» C. external short-circuits | |
| 25. |
The interaction between a transmission line and communication line is minimized by |
| A. | transposing transmission as well as communication lines |
| B. | increasing the height of the trans-mission line tower |
| C. | increasing the distance between the two lines |
| D. | all of the above |
| Answer» E. | |
| 26. |
________ relay is preferred for phase fault on short transmission line. |
| A. | Induction type |
| B. | Reactance |
| C. | Impedance |
| D. | None of the above |
| Answer» C. Impedance | |
| 27. |
H.R.C. fuse, as compared to a rewirable fuse, has |
| A. | no ageing effect |
| B. | high speed of operation |
| C. | high rupturing capacity |
| D. | all of the above |
| Answer» E. | |
| 28. |
Overload relays are of type. |
| A. | induction |
| B. | solid state |
| C. | thermal |
| D. | electromagnetic |
| E. | all above |
| Answer» F. | |
| 29. |
The arc voltage produced in A.C. circuit breaker is always |
| A. | In phase with the arc current |
| B. | Lagging the arc current by 90° |
| C. | Leading the arc current by 90° |
| D. | None of the above |
| Answer» B. Lagging the arc current by 90¬¨‚àû | |