CARNOT CYCLE MULTIPLE CHOICE QUESTIONS (MCQ) WITH ANSWERS
CARNOT CYCLE MULTIPLE
CHOICE QUESTIONS
(MCQ) WITH ANSWERS
MCQ help in better understanding.
Carnot Cycle is a most efficient power
producing cycle. It has two isentropic and
two isothermal processes. In the Carnot
Cycle, equations are there for the change
of entropy in a process. Every process in
nature is irreversible. Entropy increases
due to irreversibility. Increase of entropy is
undesirable as it reduces availability.

Entropy of a refrigerant is zero in S.I. units at a temperature of

0^{0}C

40^{0}C

+100^{0}C

None
Ans: (ii)

Change of entropy during heating at constant pressure is equal to

C_{v}ln(T_{2}/T_{1})

(1+C_{p}) ln(V_{2}/V_{1})

C_{p}ln(T_{2}/T_{1})+ C_{p}ln(V_{2}/V_{1})

None
Ans: (i)

Under isothermal conditions, change of entropy from p_{1} to p_{2} will be

Firstly C_{p} ln(p_{2}/p_{1})

Secondly C_{v} ln(V_{2}/V_{1})_{ }

Thirdly C_{p}ln(p_{2}/p_{1}) + C_{p}ln(V_{2}/V_{1})

None
Ans: (i)

When is the change of entropy is zero under an

Constant temperature process

Iso – choric process

Constant pressure process

None
Ans: (iv)

No change of entropy during a

Adiabatic process

Constant enthalpy process

Constant internal energy process

None
Ans: (iv)

During heating at constant volume process, change of specific entropy is

C_{v }ln (p_{2}/p_{1})

_{Cp }ln (p_{2}/p_{1)}

C_{p }ln (T_{2}/T_{1})

None
Ans: (iv)

In an isothermal process, change of entropy will be

C_{p} ln (v_{2}/v_{1})

C_{v} ln (v_{2}/v_{1})

R ln (v_{2}/v_{1})

None
Ans: (iii )

General expression for the change of entropy is

R ln (v_{2}/v_{1}) + C_{p }ln(T_{2}/T_{1})

R ln (v_{2}/v_{1}) + C_{v }ln(T_{2}/T_{1})

C_{p} ln (v_{2}/v_{1}) + C_{p }ln(T_{2}/T_{1})

None
Ans: (ii)

An adiabatic process will have change of entropy as

((n—γ)/(n—1)) ln(T_{2}/T_{1})

C_{p} ((n—γ)/(n—1)) ln(T_{2}/T_{1})

C_{v} ((n—γ)/(n—1)) ln(T_{2}/T_{1})

None
Ans: (iii)

Reversible adiabatic process will have change of entropy as

C_{v} ((n—γ)/(n—1)) ln(T_{2}/T_{1})

C_{p} ((n—γ)/(n—1)) ln(T_{2}/T_{1})

((n—γ)/(n—1)) ln(T_{2}/T_{1})

None
Ans: (iv)

During an irreversible process, there is

Increase of entropy

Decrease of entropy

No change in entropy

None
Ans: (i)

Increase of entropy is

Good

Neither good nor bad

Bad

None
Ans: (iii)

Decrease of entropy is in case of

Pressure decrease

Decrease in volume

Both decrease in pressure & volume

None
Ans: (ii)

Entropy increases with the

Addition of heat

Removal of heat

At constant heat

None
Ans:(i)

Under what conditions, entropy becomes double when

Temperature is doubled

Pressure becomes double

Volume is doubled

None
Ans: (iv)

A Carnot cycle is a

real cycle

Ideal cycle

Experimentally verified cycle

None
Ans: (b)

On a temperature entropy chart, Carnot cycle will be a

Rhombus

Rectangle

Triangle

None
Ans: (ii)

The order of processes in a Carnot Cycle is

Isothermal—isothermal—isentropic—isentropic

isentropic—isothermal–—isothermalisentropic

Isothermal—isentropic——isothermal –isentropic

None
Ans: (c)

Over the complete Carnot Cycle, entropy

increases

Decreases

No change

None
Ans:(iii)

With the rise of temperature in a system, sum of entropy of a system and its surroundings

Increases

Decreases

Remains constant

None
Ans: (iii)

While there is rise of pressure in a system, sum of entropy of a system and its surroundings

Increases

Decreases

Remains constant

None
Ans: (iii)

A petrol engine assumed to work on Carnot Cycle. It works between temperatures of 1200^{0}C and 200^{0} .The efficiency of the engine will be

99 %

79 %

69 %

None
Ans: (iii)

Work done will be maximum using pv^{n}=Constant when the value of index ‘n’ will be

1

4

3

None
Ans: (ii)

Minimum Work will be done using pv^{n}=Constant when the value of index ‘n’ will be

1

4

3

None
Ans: (i)

Compression ratio in a diesel cycle/petrol cycle is approximately equal to

25

5

15

None
Ans: (ii)
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