Power Systems – Multiple Choice Questions (MCQs)

1. 37. Which of the following is a disadvantage of AC transmission over DC transmission?

   • A. Higher losses
   • B. Skin effect
   • C. Corona effect
   • D. All of the above

2. 38. What is the function of a governor in a power plant?

   • A. To control turbine speed
   • B. To regulate generator voltage
   • C. To control reactive power
   • D. To limit fault current

3. 39. The term 'islanding' in power systems refers to:

   • A. A part of the power system getting disconnected from the main grid
   • B. Connecting multiple generators in parallel
   • C. A remote power plant
   • D. A fully stable system

4. 40. Which type of insulator is commonly used for high voltage transmission lines?

   • A. Pin type
   • B. Suspension type
   • C. Shackle type
   • D. Strain type

5. 41. The unit of reactive power is:

   • A. Watts
   • B. Volt-Amperes (VA)
   • C. Volt-Ampere Reactive (VAR)
   • D. Joules

6. 42. The purpose of a neutral grounding transformer is to:

   • A. Limit fault current
   • B. Provide a neutral point
   • C. Reduce overvoltages
   • D. All of the above

7. 43. Maximum demand in a power system is the:

   • A. Average load over a period
   • B. Peak load occurring in a period
   • C. Minimum load in a period
   • D. Rated capacity of the plant

8. 44. Which component protects a transformer from internal faults caused by oil decomposition?

   • A. Buchholz relay
   • B. Overcurrent relay
   • C. Differential relay
   • D. Pressure relief valve

9. 45. The maximum efficiency of a transformer occurs at:

   • A. Full load
   • B. Half load
   • C. No load
   • D. When copper losses equal iron losses

10. 46. What is the typical power factor of an inductive load?

    • A. Leading
    • B. Lagging
    • C. Unity
    • D. Zero

11. 47. The frequency of an AC power system is determined by the:

    • A. Generator speed
    • B. Transformer ratio
    • C. Load type
    • D. Transmission line length

12. 48. Which of the following is a factor affecting the choice of transmission voltage?

    • A. Length of transmission line
    • B. Amount of power to be transmitted
    • C. Economic considerations
    • D. All of the above