Thermodynamics MCQs

1. The amount of heat obtained by the complete combustion of 1 kg of a fuel when the products of its combustion are cooled down to the temperature of supplied air is called __________ calorific value offuel.

higher

lower

✅ The correct answer is option A.

2. When the expansion or compression takes place according to the law pvn = C, the process is known as

isothermal process

adiabatic process

hyperbolic process

polytropic process

✅ The correct answer is option D.

3. The universal gas constant (or molar constant) of a gas is the product of

molecular mass of the gas and the gas constant

atomic mass of the gas and the gas constant

molecular mass of the gas and the specific heat at constant pressure

molecular mass of the

✅ The correct answer is option A.

4. Select the wrong statement

A Joule cycle consists of two constant volume and two isentropic processes.

An Otto cycle consists of two constant volume and two isentropic processes.

An Ericsson cycle consists of two constant pressure and two isothermal processes.

all of the above

✅ The correct answer is option A.

5. Kerosene is distilled at

65° to 220°C

220° to 345°C

345° to 470°C

470° to 550°C

✅ The correct answer is option B.

6. By decreasing the highest temperature in the Carnot cycle, its efficiency is increased.

TRUE

FALSE

✅ The correct answer is option B.

7. Carnot cycle has maximum efficiency for

petrol engine

diesel engine

reversible engine

irreversible engine

✅ The correct answer is option C.

8. The heating of a gas at constant pressure is governed by

Boyle’s law

Charles’ law

Gay-Lussac law

Avogadro’s law

✅ The correct answer is option B.

9. A molecule consisting of one atom is known as

monoatomic

diatomic

triatomic

polyatomic

✅ The correct answer is option A.

10. Producer gas is obtained by

partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast

carbonisation of bituminous coal

passing steam over incandescent coke

passing air and a larg

✅ The correct answer is option A.