Power Plant Engineering Multiple Choice Questions and Answers

1. The overall efficiency of a boiler in a thermal power plant is of the order of

1. 10%
2. 25 to 30%
3. 40 to 50%
4. 70 to 80%.

2. Permissible pH value of water for boilers is

1. 1
2. 7
3. slightly more than 7
4. 10

3. Heating value of coal is approximately

1. 1000-2000 kcal / kg
2. 2000-4000 kcal / kg
3. 5000-6500 kcal / kg
4. 9000-10,500 kcal / kg

4. The steam consumption per kWh of electricity generated in a modem power plant is of the order of

1. 1-2 kgs
2. 2-4 kgs
3. 5-7 kgs
4. 10-12 kgs.

5. What is the maximum size of steam turbine usually being installed, for thermal power plants ?

1. 120 MW
2. 250 MW
3. 500 MW
4. 1000 MW.

6. Which of the following is not the voltage at which power is usually transmitted(A)132 kV

1. 132kV
2. 66 kV
3. 33 kV
4. 20 kV.

7. Overall thermal efficiency of a steam power station is in the range

1. 18-24%
2. 30-40%
3. 44-62%
4. 68-79%.

8. Most of the generators in thermal power plants run at

1. 3000 rpm
2. 1500 rpm
3. 1000 rpm
4. 750 rpm.

9. Standard frequency usually for electric supply is

1. 50 Hz
2. 60 Hz
3. 50 to 60 Hz
4. 50 to 55 Hz.

10. A 100 MW thermal power-plant will consume nearly how many tonnes of coal in one hour ?

1. 50 tonnes
2. 150 tonnes
3. 1500 tonnes
4. 15,000 tonnes.