Q1. The area under the load curve represents:
A. Maximum demand
B. Average load
C. Energy generated
D. Load factor
Correct Option: 3
Explanation:
A load curve plots load versus time. The area under this curve equals ∫Load·dt, whose unit is kW×h = kWh. Hence, it represents the total electrical energy generated or consumed during the given period.
Q2. Load Duration Curve is obtained by:
A. Plotting load vs time
B. Arranging load in descending order
C. Arranging load in ascending order
D. Plotting energy vs time
Correct Option: 2
Explanation:
A load duration curve is derived from the load curve by rearranging load values in descending order, ignoring the time sequence. It is useful for economic planning of power plants.
Q3. Which load remains almost constant throughout the day?
A. Domestic load
B. Industrial load
C. Commercial load
D. Agricultural load
Correct Option: 2
Explanation:
Industrial load remains nearly constant because heavy machinery operates continuously for fixed working hours, resulting in stable demand and high load factor.
Q4. Which of the following has highest diversity factor?
A. Generating station
B. Transmission system
C. Distribution feeder
D. Individual consumer
Correct Option: 3
Explanation:
Diversity factor increases as number of consumers increases. It is highest at distribution feeder level because all consumers do not use maximum load simultaneously.
Q5. If maximum demand = 100 MW and average load = 60 MW, load factor is:
A. 0.4
B. 0.6
C. 1.67
D. 0.75
Correct Option: 2
Explanation:
Load factor = Average load / Maximum demand = 60 / 100 = 0.6.
Q6. Demand factor is always:
A. Greater than 1
B. Less than 1
C. Equal to 1
D. Zero
Correct Option: 2
Explanation:
Demand factor = Maximum demand / Connected load. Since maximum demand is always less than connected load, demand factor is always less than 1.
Q7. Which load curve is most useful for selection of base-load and peak-load plants?
A. Daily load curve
B. Monthly load curve
C. Annual load curve
D. Load duration curve
Correct Option: 4
Explanation:
Load duration curve shows how long a particular load persists, helping in selecting base-load, intermediate, and peak-load generating plants.
Q8. Which plant is most suitable for base load operation?
A. Diesel power plant
B. Gas turbine plant
C. Nuclear power plant
D. Pumped storage plant
Correct Option: 3
Explanation:
Nuclear plants have high capital cost, low running cost, and are not suitable for frequent load changes, hence used for continuous base-load operation.
Q9. Commercial load mainly depends upon:
A. Climate
B. Industrial process
C. Office working hours
D. Irrigation cycle
Correct Option: 3
Explanation:
Commercial load varies with office timings, shops, markets, and business hours rather than climate or irrigation cycles.
Q10. Which factor helps in reducing installed capacity?
A. High demand factor
B. Low diversity factor
C. High diversity factor
D. Low load factor
Correct Option: 3
Explanation:
High diversity factor reduces combined maximum demand, thereby lowering required installed generating capacity.
Q11. A power station has maximum demand of 50 MW and annual energy generation of 262.8 million kWh. Load factor is:
A. 0.4
B. 0.5
C. 0.6
D. 0.75
Correct Option: 3
Explanation:
Load factor = Annual energy / (Maximum demand × 8760) = 262.8×10⁶ / (50×10³×8760) = 0.6.
Q12. Connected load = 500 kW, Maximum demand = 350 kW. Demand factor is:
A. 0.5
B. 0.7
C. 1.43
D. 0.35
Correct Option: 2
Explanation:
Demand factor = Maximum demand / Connected load = 350 / 500 = 0.7.
Q13. Maximum demand of two feeders is 100 kW and 80 kW. Combined maximum demand is 140 kW. Diversity factor is:
A. 1.14
B. 1.29
C. 0.7
D. 1.8
Correct Option: 2
Explanation:
Diversity factor = (100 + 80) / 140 = 1.29.
Q14. If a plant operates at full load for 6 hours/day and half load for 6 hours/day, load factor is:
A. 0.25
B. 0.5
C. 0.75
D. 0.6
Correct Option: 3
Explanation:
Average load = (1×6 + 0.5×6) / 12 = 0.75. Hence, load factor = 0.75.
Q15. Maximum demand = 120 MW, Load factor = 0.5. Annual energy generated (MU) is:
A. 262.8
B. 438
C. 525.6
D. 657
Correct Option: 3
Explanation:
Energy = Maximum demand × Load factor × 8760 = 120 × 0.5 × 8760 = 525.6 MU.
Q16. Connected load = 2000 kW, Demand factor = 0.6. Maximum demand is:
A. 1200 kW
B. 800 kW
C. 2000 kW
D. 3333 kW
Correct Option: 1
Explanation:
Maximum demand = Connected load × Demand factor = 2000 × 0.6 = 1200 kW.
Q17. Sum of individual maximum demands = 300 kW, Group maximum demand = 200 kW. Diversity factor is:
A. 0.67
B. 1.5
C. 2
D. 1
Correct Option: 2
Explanation:
Diversity factor = 300 / 200 = 1.5.
Q18. Which plant is preferred for peak load?
A. Steam plant
B. Nuclear plant
C. Gas turbine plant
D. Hydro base plant
Correct Option: 3
Explanation:
Gas turbine plants have quick starting and fast load response, making them ideal for peak-load operation.
Q19. Annual load factor is 0.4 and maximum demand is 100 MW. Average load is:
A. 40 MW
B. 60 MW
C. 25 MW
D. 80 MW
Correct Option: 1
Explanation:
Average load = Load factor × Maximum demand = 0.4 × 100 = 40 MW.
Q20. If diversity factor increases, total installed capacity will:
A. Increase
B. Decrease
C. Remain same
D. Become zero
Correct Option: 2
Explanation:
Increase in diversity factor reduces combined maximum demand, hence required installed capacity decreases.