Engineering Thermodynamics MCQs

Question 1

The efficiency of a gas turbine is given by

Accepted Answer

$$\frac{{{	ext{Net work output}}}}{{{	ext{Heat supplied}}}}$$

Answer

$$\frac{{{	ext{Net work output}}}}{{{	ext{Work done by the turbine}}}}$$

Answer

$$\frac{{{	ext{Actual temperature drop}}}}{{{	ext{Isentropic temperature drop}}}}$$

Answer

$$\frac{{{	ext{Isentropic increase in temperature}}}}{{{	ext{Actual increase in temperature}}}}$$

Question 2

One kg of carbon monoxide requires __________ kg of oxygen to produce $$\frac{{11}}{7}$$ kg of carbon dioxide gas.

Accepted Answer

$$\frac{4}{7}$$

Answer

$$\frac{{11}}{4}$$

Answer

$$\frac{9}{7}$$

Answer

All of these

Question 3

One kg of carbon monoxide requires _________ kg of oxygen to produce $$\frac{{11}}{7}$$ kg of carbon dioxide gas.

Accepted Answer

$$\frac{4}{7}$$

Answer

$$\frac{{11}}{7}$$

Answer

$$\frac{9}{7}$$

Answer

All of the above

Question 4

The heating of a gas at constant pressure is governed by

Accepted Answer

Charle's law

Answer

Boyle's law

Answer

Gay-Lussac law

Answer

Avogadro's law

Question 5

One reversible heat engine operates between 1600 K and T2 K and another reversible heat engine operates between T2 K and 400 K. If both the engines have the same heat input and output, then temperature T2 is equal to

Accepted Answer

800 K

Answer

1000 K

Answer

1200 K

Answer

1400 K

Question 6

Charle's law states that all perfect gases change in volume by __________ of its original volume at 0°C for every 1°C change in temperature, when pressure remains constant.

Accepted Answer

$${\frac{1}{{273}}^{{	ext{th}}}}$$

Answer

$${\frac{1}{{27}}^{{	ext{th}}}}$$

Answer

$${\frac{1}{{93}}^{{	ext{th}}}}$$

Answer

$${\frac{1}{{173}}^{{	ext{th}}}}$$

Question 7

When wood is heated with a limited supply of air to a temperature not less than 280°C, the resulting fuel is

Accepted Answer

Wood charcoal

Answer

Coke

Answer

Bituminous coal

Answer

Briquetted coal

Question 8

Which of the following cycles is not a reversible cycle?

Accepted Answer

None of the above

Answer

Carnot

Answer

Ericsson

Answer

Stirling

Question 9

Which of the following is an irreversible cycle?

Accepted Answer

None of the above

Answer

Carnot

Answer

Stirling

Answer

Ericsson