MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 25 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Which of the following medium is employed for extinction of arc in air circuit breaker ? |
| A. | Water |
| B. | Oil |
| C. | Air |
| D. | SF6 |
| Answer» D. SF6 | |
| 2. |
Thermal overload relays are used to protect the motor against over current due to |
| A. | short-circuits |
| B. | heavy loads |
| C. | grounds |
| D. | all of the above |
| Answer» C. grounds | |
| 3. |
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. | |
| 4. |
the most efficient torque producing actuating structure for the induction type relays is |
| A. | Shaded pole structure |
| B. | Watt hour meter structure |
| C. | Induction cup structure |
| D. | Single induction loop structure |
| Answer» D. Single induction loop structure | |
| 5. |
By which of the following methods major portion of the heat generated in a H.R.C. fuse is dissipated ? |
| A. | Radiation |
| B. | Convection |
| C. | Conduction |
| D. | All of the above |
| Answer» D. All of the above | |
| 6. |
The information to the circuit breaker under fault conditions is provided by |
| A. | relay |
| B. | rewirable fuse |
| C. | H.R.C. only |
| D. | all of the above |
| Answer» B. rewirable fuse | |
| 7. |
Which device is used for protection of equipment from from damage caused by overload or short circuit? |
| A. | CVT |
| B. | Circuit Breaker |
| C. | Current Transformer |
| D. | Lighting Arrester |
| Answer» C. Current Transformer | |
| 8. |
For measuring positive, negative and zero sequence voltages in a system, the reference is taken as |
| A. | Neutral of the system only. |
| B. | Ground only. |
| C. | For zero sequence neutral and for positive and negative the ground. |
| D. | None of the above. |
| Answer» E. | |
| 9. |
If the time of operating of a relay for unity TMS is 10secs., the time of operation for 0.5 TMS will be |
| A. | 20 secs. |
| B. | 5 secs. |
| C. | 10 secs. |
| D. | None of the above |
| Answer» C. 10 secs. | |
| 10. |
Phase comparators in case of static relays and electro-mechanical relays normally are |
| A. | Sine and cosine comparators respectively |
| B. | Cosine and sine comparators respectively. |
| C. | Both are cosine comparators. |
| D. | Both are sing comparators. |
| Answer» C. Both are cosine comparators. | |
| 11. |
Protective relays are devices that detect abnormal conditions in electrical circuits by measuring |
| A. | current during abnormal condition |
| B. | voltage during abnormal condition |
| C. | constantly the electrical quantities which differ during normal and abnormal conditions |
| D. | none of the above |
| Answer» D. none of the above | |
| 12. |
Discrimination between main and back up protection is provided by the use of relays which are |
| A. | fact |
| B. | sensitive |
| C. | slow |
| D. | none of the above |
| Answer» D. none of the above | |
| 13. |
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 | |
| 14. |
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. | |
| 15. |
For cost and safety, the outdoor substations are installed for voltages above |
| A. | 11 kV |
| B. | 33 kV |
| C. | 60kV |
| D. | 110kV |
| Answer» C. 60kV | |
| 16. |
For which of the following protection from negative sequence currents is provided? |
| A. | Generators |
| B. | Motors |
| C. | Transmission line |
| D. | Tr |
| Answer» B. Motors | |
| 17. |
A _______ is used to measure the stator % winding temperature of the generator. |
| A. | thermocouple |
| B. | pyrometer |
| C. | resistance thermometer |
| D. | thermometer |
| Answer» D. thermometer | |
| 18. |
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 | |
| 19. |
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 |
| Answer» C. equal to and above 25 MVA | |
| 20. |
Which of the following circuit breakers has high reliability and minimum maintenance ? |
| A. | Air blast circuit breakers |
| B. | Circuit breaker with SF6 gas |
| C. | Vacuum circuit breakers |
| D. | Oil circuit breakers |
| Answer» C. Vacuum circuit breakers | |
| 21. |
Air blast circuit breakers for 400 kV power system are designed to operate in |
| A. | 100 microsecond |
| B. | 50 millisecond |
| C. | 0.5 sec |
| D. | 0.1 sec |
| Answer» C. 0.5 sec | |
| 22. |
Ungrounded neutral transmission system is not recommended because of system |
| A. | insulation being overstressed due to over voltages |
| B. | insulation overstress may lead to failure and subsequent phase to phase faults |
| C. | being inadequately protected against ground fault |
| D. | all of the above |
| Answer» E. | |
| 23. |
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 | |
| 24. |
When a transmission line is energized, the wave that propagates on it is |
| A. | current wave only |
| B. | voltage wave only |
| C. | both (a) and (b) |
| D. | power factor wave only |
| Answer» D. power factor wave only | |
| 25. |
The reflection co-efficient at the open circuited end of a transmission line. |
| A. | zero |
| B. | infinity |
| C. | unity |
| D. | none of the above |
| Answer» D. none of the above | |