Engineering Thermodynamics (3131905) MCQs

MCQs of Second Law of Thermodynamics

Showing 11 to 20 out of 27 Questions
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11.

The work done by a closed system in a reversible process is always ___ that done in an irreversible process.

(a)

more than
(b)

equal to
(c)

less than
(d)

all of these
Answer:

Option (d)

12.

The efficiency of a Carnot engine is given as 0.75. If the cycle direction is reversed, what will be the value of COP of reversed Carnot cycle

(a)

0.75
(b)

0.33
(c)

1.33
(d)

0.25
Answer:

Option (c)

13.

Kelvin-Planck's law deals with

(a)

conservation of work
(b)

conservation of heat
(c)

conversion of heat into work
(d)

conversion of work into heat
Answer:

Option (c)

14.

According to Kelvin-Planck's statement a perpeual motion machine of  the ____________is impossible.

(a)

first kind
(b)

second kind
(c)

third kind
(d)

none of these
Answer:

Option (b)

15.

Which of the following is the correct statement of the second law of thermodynamics?

(a)

It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
(b)

It is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
(c)

There is a definite amount of mechanical energy, which can be obtained from a given quantity of heat energy
(d)

All of these
Answer:

Option (d)

16.

The heat flows from a cold body to a hot body with the aid of an external source. This statement is given by

(a)

Kelvin
(b)

Joule
(c)

Clausius
(d)

Gay-Lussac
Answer:

Option (c)

17.

In an irreversible process, there is a

(a)

loss of heat
(b)

no loss of heat
(c)

gain of heat
(d)

no gain of heat
Answer:

Option (a)

18.

The main cause for the irreversibility is

(a)

mechanical and fluid friction
(b)

unrestricted expansion
(c)

heat transfer with a finite temperature difference
(d)

all of these
Answer:

Option (d)

19.

The condition for the reversibility of a cycle is

(a)

the pressure and temperature of the working substance must not differ, appreciably, from those of the surroundings at any stage in the process
(b)

all the processes, taking place in the cycle of operation, must be extremely slow
(c)

the working parts of the engine must be friction free
(d)

all of these
Answer:

Option (d)

20.

Which is incorrect statement about the reversible process?

(a)

A reversible process is ideal
(b)

A reversible process when undone, will leave no history of the events in the surroundings
(c)

A reversible process must pass through a continuous series of equilibrium states
(d)

None of these
Answer:

Option (d)

Showing 11 to 20 out of 27 Questions
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