Power Generations MCQs Part 15

Contents

- 1 To supply base load of power plant, which of the following powerplant is very suitable
- 2 A diesel power station has fuel consumption of 0.3 per kWh. The calorific value of fuel being 9898 kcal/kg. The overall efficiency of station is
- 3 When moving from consumers to power station, the diversity factor of a power plant:
- 4 Mechanical energy is supplied to a DC generator at rate of 90 J/s. The generator delivers 40 at 90 V. The efficiency of generator is:
- 5 A diesel power station has fuel consumption of 0.3 per kWh. The calorific value of fuel being 9800 kcal/kg. If alternator efficiency is 96%. The efficiency of engine is

## 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
- Gas
- None of these

Correct answer: 2. Nuclear

Explanation: Base load power plants deliver full power at all times. Coal fired power stations and nuclear power stations are particularly suitable for meeting the base load demands.

## A diesel power station has fuel consumption of 0.3 per kWh. The calorific value of fuel being 9898 kcal/kg. The overall efficiency of station is

A diesel power station has fuel consumption of 0.3 per kWh. The calorific value of fuel being 9898 kcal/kg. The overall efficiency of station is:

- 28.96%
- 33.96%
- 38.96%
- 43.96%

Correct answer: 1. 28.96%

Solution:

Heat produced by 0.3 kg of oil = 9898 * 0.3 = 2969.4 kcal

—————

Heat equivalent of 1 kWh = 860 kcal

—————

Overall efficiency = Electrical output/Heat of combustion = 860/2969.4 = 0.2896 = 28.96%

## When moving from consumers to power station, the diversity factor of a power plant:

When moving from consumers to power station, the diversity factor of a power plant:

- Increases
- Remains the same
- Decreases
- None of these

Correct answer: 3. Decreases

## Mechanical energy is supplied to a DC generator at rate of 90 J/s. The generator delivers 40 at 90 V. The efficiency of generator is:

Mechanical energy is supplied to a DC generator at rate of 90 J/s. The generator delivers 40 at 90 V. The efficiency of generator is:

- 33784
- 32784
- 31784
- 30784

Correct answer: 3. 31784

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 = 0.9 * 35316 = 31784 kW

## A diesel power station has fuel consumption of 0.3 per kWh. The calorific value of fuel being 9800 kcal/kg. If alternator efficiency is 96%. The efficiency of engine is

A diesel power station has fuel consumption of 0.3 per kWh. The calorific value of fuel being 9800 kcal/kg. If alternator efficiency is 96%. The efficiency of engine is:

- 23.47%
- 30.47%
- 37.47%
- 44.47%

Correct answer: 2. 30.47%

Solution:

Heat produced by 0.3 kg of oil = 9800 * 0.3 = 2940 kcal

—————

Heat equivalent of 1 kWh = 860 kcal

—————

Overall efficiency = Electrical output/Heat of combustion = 860/2940 = 0.292517006802721 = 29.25%

—————

Engine efficiency = Overall efficiency/Alternator efficiency = 29.25/0.96 = 30.47%