Power Systems – Multiple Choice Questions (MCQs)

1. 13. The term 'diversity factor' in power systems is defined as:

   • A. Sum of individual maximum demands / Maximum demand on power station
   • B. Maximum demand on power station / Sum of individual maximum demands
   • C. Average load / Maximum demand
   • D. Connected load / Maximum demand

2. 14. Corona loss in transmission lines increases with:

   • A. Increase in conductor diameter
   • B. Decrease in atmospheric pressure
   • C. Decrease in frequency
   • D. Increase in conductor spacing

3. 15. Which type of fault is most common in a power system?

   • A. Single line-to-ground fault
   • B. Line-to-line fault
   • C. Double line-to-ground fault
   • D. Three-phase fault

4. 16. A synchronous condenser is used to:

   • A. Improve power factor
   • B. Reduce voltage
   • C. Increase active power
   • D. Stabilize frequency

5. 17. The purpose of earthing (grounding) in a power system is to:

   • A. Provide a path for fault currents
   • B. Improve voltage regulation
   • C. Increase system efficiency
   • D. Reduce power losses

6. 18. What is the typical operating frequency of AC power systems in India?

   • A. 50 Hz
   • B. 60 Hz
   • C. 400 Hz
   • D. 25 Hz

7. 19. Which type of circuit breaker uses SF6 gas for arc quenching?

   • A. Oil circuit breaker
   • B. Air blast circuit breaker
   • C. Vacuum circuit breaker
   • D. SF6 circuit breaker

8. 20. The term 'skin effect' in transmission lines refers to:

   • A. Current flowing on the surface of the conductor
   • B. Current flowing uniformly throughout the conductor
   • C. Current flowing at the center of the conductor
   • D. Current flowing through the insulation

9. 21. What is the role of a bus bar in a substation?

   • A. To transform voltage
   • B. To protect against overcurrent
   • C. To connect various components at a common voltage
   • D. To generate reactive power

10. 22. Which factor has the least impact on the sag of a transmission line?

    • A. Ice loading
    • B. Wind pressure
    • C. Conductor weight
    • D. Frequency

11. 23. The stability of a power system refers to its ability to:

    • A. Maintain voltage within limits
    • B. Maintain frequency within limits
    • C. Remain in synchronism after a disturbance
    • D. Withstand short circuits

12. 24. What is the purpose of a surge impedance loading (SIL) in transmission lines?

    • A. To determine maximum power transfer
    • B. To calculate characteristic impedance
    • C. To define line length
    • D. To minimize voltage drop