Power Systems – Multiple Choice Questions (MCQs)

1. 49. The concept of 'base load' in power plants refers to:

   • A. The minimum load on the system
   • B. The average load on the system
   • C. The peak load on the system
   • D. The rated capacity of the plant

2. 50. What is the main function of an exciter in a synchronous generator?

   • A. To provide DC excitation to the rotor
   • B. To regulate speed
   • C. To cool the generator
   • D. To provide reactive power

3. 51. Which of the following is a characteristic of a radial distribution system?

   • A. High reliability
   • B. Complex network
   • C. Single path for power flow
   • D. Lower voltage drops

4. 52. The MVA rating of a generator is related to its:

   • A. Active power output
   • B. Reactive power output
   • C. Apparent power output
   • D. Voltage rating

5. 53. What is the significance of the short-circuit ratio (SCR) of a synchronous machine?

   • A. Indicates its voltage regulation
   • B. Indicates its transient stability
   • C. Indicates its steady-state stability
   • D. Indicates its reactance

6. 54. Which type of power plant has the highest operating costs?

   • A. Hydroelectric
   • B. Nuclear
   • C. Thermal (coal-fired)
   • D. Solar

7. 55. The term 'relay coordination' in protection systems ensures that:

   • A. Relays operate simultaneously
   • B. Relays operate in sequence
   • C. Relays are set to the same current
   • D. Relays are of the same type

8. 56. What is the purpose of an overhead ground wire (shield wire) in transmission lines?

   • A. To carry current
   • B. To reduce sag
   • C. To protect against lightning
   • D. To improve insulation

9. 57. The phenomenon of 'ferroresonance' occurs in power systems due to:

   • A. Linear inductances
   • B. Non-linear inductances
   • C. Capacitors
   • D. Resistors

10. 58. Which component is used to connect a generator to a transmission line at different voltage levels?

    • A. Circuit breaker
    • B. Isolator
    • C. Transformer
    • D. Bus bar

11. 59. What is the typical range of power factor for a well-operated power system?

    • A. 0.5 lagging to 0.5 leading
    • B. 0.8 lagging to 0.95 lagging
    • C. 0.9 lagging to unity
    • D. Unity to 0.9 leading

12. 60. The load duration curve provides information about:

    • A. The daily load variation
    • B. The annual load variation
    • C. The peak load
    • D. The energy consumed over a period