4

Which of the following will increase the volume of a real gas by four times?

Doubling the absolute temperature as well as pressure of the gas

Reducing pressure to one fourth at constant temperature

Reducing temperature to one fourth at constant pressure

Reducing the temperature to half and doubling the pressure

B. Reducing pressure to one fourth at constant temperature

4

n = y = 1.4

n = 0

n = 1

n = 1.66

4

What happens in a reversible adiabatic expansion process?

Heating takes place

Cooling takes place

Pressure is constant

Temperature is constant

4

In case of vapour compression refrigeration system, elevating the evaporator temperature (keeping the condenser temperature constant) results in

Enhanced COP

Decreased COP

No change in the value of COP

Increased or decreased COP; depending upon the type of refrigerant

4

Critical compressibility factor for all substances

Are more or less constant (vary from 0.2 to 0.3)

Vary as square of the absolute temperature

Vary as square of the absolute pressure

None of these

4

3

2

1

0

4

For an incompressible fluid, the __________ is a function of both pressure as well as temperature.

Internal energy

Enthalpy

Entropy

All (A), (B) & (C)

4

12 P1V1

6 P1 V1

3 P1V1

P1 V1

4

Isothermal

Isometric

None of these

4

100,000 kW

160,000 kW

200,000 kW

320,000 kW

4

> 2

< 1

> 1

< 3

4

72

92

142

192

4

Gibbs-Duhem

Van Laar

Gibbs-Helmholtz

Margules

4

A Carnot cycle consists of the following steps:

Two isothermal and two isentropic

Two isobaric and two isothermal

Two isochoric and two isobaric

Two isothermals and two isochoric

4

The necessary and sufficient condition for equilibrium between two phases is

The concentration of each component should be same in the two phases

The temperature of each phase should be same

The pressure should be same in the two phases

The chemical potential of each component should be same in the two phases

4

Less than

Same as

More than

Half

4

R loge 4

R log10 4

Cv log10 4

Cv loge 4

4

A solid is transformed into vapour without going to the liquid phase at

Triple point

Boiling point

Below triple point

Always

4

Pick out the wrong statement.

Surface tension of a substance vanishes at critical point, as there is no distinction between liquid and vapour phases at its critical point

Entropy of a system decreases with the evolution of heat

Change of internal energy is negative for exothermic reactions

The eccentric factor for all materials is always more than one

4

349

651

667

1000

4

1

2

3

4

4

First law of thermodynamics deals with the

Direction of energy transfer

Reversible processes only

Irreversible processes only

None of these

4

Which of the following is affected by the temperature?

Fugacity

Activity co-efficient

Free energy

All (A), (B) & (C)

4

The expression for entropy change given by, ΔS = nR ln (V2/V1) + nCv ln (T2/T1) is valid for

Reversible isothermal volume change

Heating of a substance

Cooling of a substance

Simultaneous heating and expansion of an ideal gas

4

0

+ve

-ve

4

The chemical potential of any constituent of an ideal solution depends on the __________ of the solution.

Temperature

Pressure

Composition

All (A), (B) and (C)

4

In any spontaneous process,

Only F decreases

Only A decreases

Both F and A decreases

Both F and A increase

4

0

1

2

3

4

0

50

100

4

Isothermally

Isobarically

None of these