# Thermodynamics Questions and Answers – Carnot Cycle, Stirling Cycle and Ericsson Cycle

«
»

This set of Thermodynamics Multiple Choice Questions & Answers (MCQs) focuses on “Efficiencies in Steam Power Plant “.

1. In a gas power cycle,
a) the working fluid is gas
b) it does not undergo phase change
c) engines which operate on gas cycle can be cyclic or non-cyclic
d) all of the mentioned

Explanation: These are basic facts about gas power cycles.

2. A Carnot cycle consists of
a) two reversible isotherms and two reversible isobars
b) two reversible isotherms and two reversible adiabatics
c) two reversible isotherms and two reversible isochores
d) two reversible isobars and two reversible adiabatics

Explanation: This is what a Carnot cycle means.

3. The efficiency of a Carnot cycle is given by
a) 1 – (T1/T2)
b) heat supplied / net work
c) net work / heat supplied
d) all of the mentioned

Explanation: Here T1 is the temperature of heat addition and T2 is the temperature of heat rejection.

4. For a Carnot cycle, the large back work is a big disadvantage.
a) true
b) false

Explanation: This is true for both Carnot gas cycle and Carnot vapour cycle.

5. The Stirling cycle consists of
a) two reversible isotherms and two reversible isobars
b) two reversible isotherms and two reversible adiabatics
c) two reversible isotherms and two reversible isochores
d) two reversible isobars and two reversible adiabatics

Explanation: The Stirling cycle consists of these processes.

6. The efficiency of Stirling cycle is ____ the efficiency of Carnot cycle.
a) more than
b) less than
c) equal to
d) none of the mentioned

Explanation: The reason being in Stirling cycle, heat transfers are constant volume processes.

7. The efficiency of regenerative Stirling cycle is ____ the efficiency of Carnot cycle.
a) more than
b) less than
c) equal to
d) none of the mentioned

Explanation: This is because of the regenerative arrangement used.

8. The Ericsson cycle consists of
a) two reversible isotherms and two reversible isobars
b) two reversible isotherms and two reversible adiabatics
c) two reversible isotherms and two reversible isochores
d) two reversible isobars and two reversible adiabatics

Explanation: The Ericsson cycle is made up of these processes.

9. The efficiency of Ericsson cycle is ____ the efficiency of Carnot cycle.
a) more than
b) less than
c) equal to
d) none of the mentioned

Explanation: In Ericsson cycle, part of heat is transferred at constant temperature and part at constant pressure.

10. The regenerative, Stirling and Ericsson cycles have same efficiency as Carnot cycle.
a) true
b) false 