Power Systems – Multiple Choice Questions (MCQs)

1. 85. What is the 'unit commitment' problem in power system operation?

   • A. Deciding which generating units to start up or shut down
   • B. Determining the optimal transmission line configuration
   • C. Scheduling maintenance activities
   • D. Forecasting load demand

2. 86. The economic dispatch problem aims to:

   • A. Minimize generation cost for a given load
   • B. Maximize power output
   • C. Optimize transmission line capacity
   • D. Reduce environmental impact

3. 87. Which of the following is an advantage of pumped hydro storage?

   • A. High efficiency
   • B. Fast response time
   • C. Can be used for peak shaving
   • D. All of the above

4. 88. The term 'spinning reserve' is crucial for maintaining:

   • A. Voltage stability
   • B. Frequency stability
   • C. Reactive power balance
   • D. Power factor

5. 89. What is the role of a step-down transformer in a distribution substation?

   • A. To increase voltage for transmission
   • B. To decrease voltage for consumption
   • C. To convert AC to DC
   • D. To store energy

6. 90. Which type of earthing system provides the best protection against electric shock?

   • A. Solidly earthed system
   • B. Resistance earthed system
   • C. Reactance earthed system
   • D. Resonant earthed system

7. 91. The 'voltage flickers' in a power system are caused by:

   • A. Sudden changes in load
   • B. Steady-state loads
   • C. Reactive power compensation
   • D. Generator overspeed

8. 92. Which of the following is a primary protective scheme?

   • A. Distance protection
   • B. Backup protection
   • C. Unit protection
   • D. All of the above

9. 93. The load factor of a power plant is a measure of its:

   • A. Efficiency
   • B. Utilization
   • C. Reliability
   • D. Capacity

10. 94. What is the main challenge in integrating large-scale renewable energy sources into the grid?

    • A. Intermittency
    • B. High fuel cost
    • C. High transmission losses
    • D. Lack of suitable locations

11. 95. The concept of 'ancillary services' in power systems includes:

    • A. Energy generation
    • B. Transmission line construction
    • C. Frequency regulation and voltage control
    • D. Fuel procurement

12. 96. Which type of power plant is known for its quick start-up time and ability to handle peak loads?

    • A. Coal-fired thermal
    • B. Nuclear
    • C. Gas turbine
    • D. Hydroelectric