MCQOPTIONS
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MCQOPTIONS
This section includes 129 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. |
The steady state stability of the power system can be increased by |
| A. | Connecting lines in parallel |
| B. | Connecting lines in series |
| C. | Using machines of high impedance |
| D. | Reducing the excitation of machines |
| Answer» B. Connecting lines in series | |
| 2. |
Air blast circuit breaker is used for |
| A. | over currents |
| B. | short duty |
| C. | intermittant duty |
| D. | repeated duty |
| Answer» E. | |
| 3. |
The arcing contacts in a circuit breaker are made of |
| A. | copper tungsten alloy |
| B. | porcelain |
| C. | electrolytic copper |
| D. | aluminium alloy |
| Answer» B. porcelain | |
| 4. |
Relays can be designed to respond to changes in |
| A. | resistance, reactance or impedance |
| B. | voltage and current |
| C. | light intensity |
| D. | temperature |
| E. | all above |
| Answer» F. | |
| 5. |
Fault diverters are basically |
| A. | fuses |
| B. | relays |
| C. | fast switches |
| D. | circuit breakers |
| Answer» D. circuit breakers | |
| 6. |
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 | |
| 7. |
Oil switches are employed for |
| A. | low currents circuits |
| B. | low voltages circuits |
| C. | high voltages and large currents circuits |
| D. | all circuits |
| Answer» D. all circuits | |
| 8. |
If the fault occurs near the impedance relay, the VII ratio will be |
| A. | constant for all distances |
| B. | lower than that of if fault occurs away from the relay |
| C. | higher than that of if fault occurs away from the relay |
| D. | none of the above |
| Answer» C. higher than that of if fault occurs away from the relay | |
| 9. |
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 |
| Answer» E. | |
| 10. |
Circuit breakers are essentially |
| A. | current carrying contacts called electrodes |
| B. | arc extinguishers |
| C. | circuits to break the system |
| D. | transformers to isolate the two systems |
| E. | any of the above |
| Answer» B. arc extinguishers | |
| 11. |
Thermal circuit breaker has |
| A. | delayed trip action |
| B. | instantaneous trip action |
| C. | both of the above |
| D. | none of the above |
| Answer» B. instantaneous trip action | |
| 12. |
A thermal protection switch can protect against |
| A. | short-circuit |
| B. | temperature |
| C. | overload |
| D. | over voltage |
| Answer» D. over voltage | |
| 13. |
For which of the following protection from negative sequence currents is provided ? |
| A. | Generators |
| B. | Motors |
| C. | Transmission line |
| D. | Transformers |
| Answer» B. Motors | |
| 14. |
Distance relays are generally |
| A. | split-phase relays |
| B. | reactance relays |
| C. | impedance relays |
| D. | none of the above |
| Answer» E. | |
| 15. |
An efficient and a well designed protective relaying should have |
| A. | good selectivity and reliability |
| B. | economy and simplicity |
| C. | high speed and selectivity |
| D. | all of the above |
| Answer» E. | |
| 16. |
SF6 gas |
| A. | is yellow in colour |
| B. | is lighter than air |
| C. | is nontoxic |
| D. | has pungent small |
| E. | none of the above |
| Answer» D. has pungent small | |
| 17. |
H.R.C. fuses provide best protection against |
| A. | overload |
| B. | reverse current |
| C. | open-circuits |
| D. | short-circuits |
| Answer» E. | |
| 18. |
To reduce short circuit fault currents are used. |
| A. | reactors |
| B. | resistors |
| C. | capacitors |
| D. | none of the above |
| Answer» B. resistors | |
| 19. |
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 |
| Answer» E. | |
| 20. |
The main function of a fuse is to |
| A. | protect the line |
| B. | open the circuit |
| C. | protect the appliance |
| D. | prevent excessive currents |
| E. | none of the above |
| Answer» E. none of the above | |
| 21. |
D.C. shunt relays are made of |
| A. | few turns of thin wire |
| B. | few turns of thick wire |
| C. | many turns of thin wire |
| D. | many turns of thick wire |
| Answer» D. many turns of thick wire | |
| 22. |
The fuse wire, in D.C. circuits, is inserted in |
| A. | negative circuit only |
| B. | positive circuit only |
| C. | both (A) and (B) |
| D. | either (A) or (B) |
| Answer» D. either (A) or (B) | |
| 23. |
A short-circuit is identified by |
| A. | no current flow |
| B. | heavy current flow |
| C. | voltage drop |
| D. | voltage rise |
| Answer» C. voltage drop | |
| 24. |
In Railway applications ______ circuit breaker is used. |
| A. | SFe |
| B. | bulk oil |
| C. | minimum oil |
| D. | air break |
| Answer» E. | |
| 25. |
The fuse rating is expressed in terms of |
| A. | current |
| B. | voltage |
| C. | VAR |
| D. | kVA |
| Answer» B. voltage | |
| 26. |
The ground wire should not be smaller than No ______ copper. |
| A. | 2 |
| B. | 4 |
| C. | 6 |
| D. | 10 |
| Answer» E. | |
| 27. |
Protection by fuses is generally not used beyond |
| A. | 20 A |
| B. | 50 A |
| C. | 100 A |
| D. | 200 A |
| Answer» D. 200 A | |
| 28. |
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 | |
| 29. |
The material used for fuse must have |
| A. | low melting point and high specific resistance |
| B. | low melting point and -low specific resistance |
| C. | high melting point and low specific resistance |
| D. | low melting point and any specific resistance |
| Answer» C. high melting point and low specific resistance | |
| 30. |
Directional relays are based on flow of |
| A. | power |
| B. | current |
| C. | voltage wave |
| D. | all of the above |
| Answer» B. current | |
| 31. |
Burden of a protective relay is the power |
| A. | required to operate the circuit breaker |
| B. | absorbed by the circuit of relay |
| C. | developed by the relay circuit |
| D. | none of the above |
| Answer» C. developed by the relay circuit | |
| 32. |
Shunt capacitance is neglected while considering |
| A. | short transmission line |
| B. | medium transmission line |
| C. | long transmission line |
| D. | medium and long transmission lines |
| Answer» B. medium transmission line | |
| 33. |
Which of the following parameter can be neglected for a short line? |
| A. | Inductance |
| B. | Capacitance |
| C. | Resistance |
| D. | Reactance |
| Answer» C. Resistance | |
| 34. |
Induction cup relay is operated due to changes in |
| A. | current |
| B. | voltage |
| C. | impedance |
| D. | all of the above |
| Answer» E. | |
| 35. |
The fuse rating is expressed in terms of~! |
| A. | current |
| B. | voltage |
| C. | VAR |
| D. | kVA |
| Answer» B. voltage | |
| 36. |
The steady state stability of the power system can be increased by%! |
| A. | Connecting lines in parallel |
| B. | Connecting lines in series |
| C. | Using machines of high impedance |
| D. | Reducing the excitation of machines |
| Answer» B. Connecting lines in series | |
| 37. |
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 | |
| 38. |
*/*_H.R.C. fuses provide best protection against? |
| A. | overload |
| B. | reverse current |
| C. | open-circuits |
| D. | short-circuits |
| Answer» E. | |
| 39. |
*/*_The fuse wire, in D.C. circuits, is inserted in? |
| A. | negative circuit only |
| B. | positive circuit only |
| C. | both (A) and (B) |
| D. | either (A) or (B) |
| Answer» D. either (A) or (B) | |
| 40. |
*/*_For which of the following protection from negative sequence currents is provided ?? |
| A. | Generators |
| B. | Motors |
| C. | Transmission line |
| D. | Transformers |
| Answer» B. Motors | |
| 41. |
*/*_Shunt capacitance is neglected while considering? |
| A. | short transmission line |
| B. | medium transmission line |
| C. | long transmission line |
| D. | medium and long transmission lines |
| Answer» B. medium transmission line | |
| 42. |
*/*_The ground wire should not be smaller than No ______ copper.? |
| A. | 2 |
| B. | 4 |
| C. | 6 |
| D. | 10 |
| Answer» E. | |
| 43. |
*/*_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 | |
| 44. |
*/*_The steady state stability of the power system can be increased by? |
| A. | Connecting lines in parallel |
| B. | Connecting lines in series |
| C. | Using machines of high impedance |
| D. | Reducing the excitation of machines |
| Answer» B. Connecting lines in series | |
| 45. |
*/*_Air blast circuit breaker is used for? |
| A. | over currents |
| B. | short duty |
| C. | intermittant duty |
| D. | repeated duty |
| Answer» E. | |
| 46. |
_ To reduce short circuit fault currents are used.$? |
| A. | reactors |
| B. | resistors |
| C. | capacitors |
| D. | none of the above |
| Answer» B. resistors | |
| 47. |
_ A short-circuit is identified by$? |
| A. | no current flow |
| B. | heavy current flow |
| C. | voltage drop |
| D. | voltage rise |
| Answer» C. voltage drop | |
| 48. |
_ Distance relays are generally$? |
| A. | split-phase relays |
| B. | reactance relays |
| C. | impedance relays |
| D. | none of the above |
| Answer» E. | |
| 49. |
_ Which of the following parameter can be neglected for a short line?$? |
| A. | Inductance |
| B. | Capacitance |
| C. | Resistance |
| D. | Reactance |
| Answer» C. Resistance | |
| 50. |
_ Protection by fuses is generally not used beyond$? |
| A. | 20 A |
| B. | 50 A |
| C. | 100 A |
| D. | 200 A |
| Answer» D. 200 A | |