Power Generation MCQs Part 16

Contents

- 1 The cheapest power plant in terms of operation and maintenance is
- 2 Mechanical energy is supplied to a DC generator at rate of 90 J/s. The generator delivers 40 at 85 V. The yearly kWh output of plant is
- 3 Certain power station has an average demand of 20 MW. If plant capacity factor is 55%. The plant capacity is
- 4 If load factor of a power plant increases, the cost of power generation per unit will
- 5 To supply base load of power plant, which of the following powerplant is very suitable

## The cheapest power plant in terms of operation and maintenance is

The cheapest power plant in terms of operation and maintenance is:

- Diesel power plant
- Hydroelectric power plant
- Nuclear power plant
- Steam power plant

Correct answer: 2. Hydroelectric power plant

## Mechanical energy is supplied to a DC generator at rate of 90 J/s. The generator delivers 40 at 85 V. The yearly kWh output of plant is

Mechanical energy is supplied to a DC generator at rate of 90 J/s. The generator delivers 40 at 85 V. The yearly kWh output of plant is:

- 1013 * 10^6 kWh
- 763 * 10^6 kWh
- 513 * 10^6 kWh
- 263 * 10^6 kWh

Correct answer: 1. 263 * 10^6 kWh

Solution:

Mass of water available = 90 * 1000 = 90000 kg/sec

————

Head = 40 m

Work done/sec = W*H = 90000 * 40 = 35316 * 10³ W = 35316 kW

This is gross plant capacity.

———————

Firm capacity = Plant efficiency * Gross plant capacity

Firm capacity = 0.85 * 35316 = 262.96644 kW

———————

Output/annum = Firm capacity * Hours in a year

Output/annum = 30019 * 8760 = 263 * 10^6 kWh

## Certain power station has an average demand of 20 MW. If plant capacity factor is 55%. The plant capacity is

Certain power station has an average demand of 20 MW. If plant capacity factor is 55%. The plant capacity is:

- 21 kW
- 26 kW
- 36 kW
- 46 kW

Correct answer: 3. 36 kW

Solution:

From formula of Plant capacity factor

Plant capacity factor = Average demand/Plant capacity

Plant capacity = Average demand/Plant capacity factor = 20/0.55 = 36 MW

## If load factor of a power plant increases, the cost of power generation per unit will

If load factor of a power plant increases, the cost of power generation per unit will:

- Increase
- Remain the same
- Decrease
- None of these

Correct answer: 3. Decrease

## To supply base load of power plant, which of the following powerplant is very suitable

To supply base load of power plant, which of the following powerplant is very suitable:

- Diesel
- Nuclear
- Thermal
- None of these

Correct answer: 1. Diesel

Explanation: Peak load power stations deliver power during a few intervals in the day. Such stations must be put in service very quickly. Diesel power stations can be started and put in service within a few minutes. While thermal power plants take around 4 to 8 hours for start-up. Nuclear power plants can take several days for being in service.