250+ TOP MCQs on Kelvin-Planck Statement and Clausius’ Statement of Second Law and Answers

Thermodynamics Questions and Answers for experienced on “Kelvin-Planck Statement and Clausius’ Statement of Second Law”.

1. According to Kelvin-Planck statement, it is ____ for a heat engine to produce net work in a complete cycle if it exchanges heat only with bodies at ____
a) impossible, single fixed temperature
b) possible, changing temperature
c) impossible, changing temperature
d) possible, single fixed temperature
Answer: a
Clarification: This is the basic definition of Kelvin-Planck statement.

2. If heat rejected from the system Q2 is zero, then
a) net work=Q1 and efficiency=1.00
b) heat is exchanged only with one reservoir
c) it violates the Kelvin-Planck statement
d) all of the mentioned
Answer: d
Clarification: Such a heat engine is called a perpetual motion machine of the second kind(PMM2).

3. A PMM2 is possible.
a) true
b) false
Answer: b
Clarification: A PMM2 is impossible because it violates the Kelvin-Planck statement.

4. A heat engine has to exchange heat with ___ energy reservoir at ___ different temperatures to produce net work in a complete cycle.
a) one, one
b) one, two
c) two, two
d) none of the mentioned
Answer: c
Clarification: This is required to produce power.

5. The second law is not a deduction of the first law.
a) true
b) false
Answer: a
Clarification: The first law is a separate law of nature.

6. The continual operation of a machine that creates its own energy and thus violates the first law is called
a) PMM2
b) PMM1
c) PMM0
d) none of the mentioned
Answer: b
Clarification: This is a basic fact about PMM1.

7. Which of the following is true?
a) heat always from a high temperature body to a low temperature body
b) heat always from a low temperature body to a high temperature body
c) heat can flow from both low to high and high to low temperature body
d) none of the mentioned
Answer: a
Clarification: The reverse process never occurs spontaneously.

8. According to Clausius statement
a) it is impossible to construct a device than can transfer heat from a cooler body to a hotter body without any effect
b) it is impossible to construct a device than can transfer heat from a hotter body to a cooler body without any effect
c) it is possible to construct a device than can transfer heat from a cooler body to a hotter body without any effect
d) none of the mentioned
Answer: a
Clarification: To transfer heat from a cooler body to a hotter body, some work must be expended.

9. If the second law were not true
a) a ship could be driven by extracting heat from the ocean
b) run a power plant by extracting heat from the air
c) both of the mentioned
d) none of the mentioned
Answer: c
Clarification: Both of the above possibilities do not violate the first law but do violate the second law.

10. The operation of a machine that utilizes the internal energy of only one TER, thus violating second law is called
a) PMM0
b) PMM1
c) PMM2
d) none of the mentioned
Answer: b
Clarification: PMM2 violates the second law.

Thermodynamics for Experienced,

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