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4

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

A. Doubling the absolute temperature as well as pressure of the gas

B. Reducing pressure to one fourth at constant temperature

C. Reducing temperature to one fourth at constant pressure

D. Reducing the temperature to half and doubling the pressure

Correct Answer :

B. Reducing pressure to one fourth at constant temperature


Related Questions

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4

In case of steady flow compression polytropic process (PVn = constant), the work done on air is the lowest, when

A. n = y = 1.4

B. n = 0

C. n = 1

D. n = 1.66

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4

What happens in a reversible adiabatic expansion process?

A. Heating takes place

B. Cooling takes place

C. Pressure is constant

D. Temperature is constant

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4

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

A. Enhanced COP

B. Decreased COP

C. No change in the value of COP

D. Increased or decreased COP; depending upon the type of refrigerant

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4

Critical compressibility factor for all substances

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

B. Vary as square of the absolute temperature

C. Vary as square of the absolute pressure

D. None of these

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4

The number of degrees of freedom for a mixture of ice and water (liquid) are

A. 3

B. 2

C. 1

D. 0

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4

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

A. Internal energy

B. Enthalpy

C. Entropy

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

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4

An ideal gas is taken around the cycle ABCA as shown in P-V diagram below: The work done by the gas during the cycle is equal to

A. 12 P1V1

B. 6 P1 V1

C. 3 P1V1

D. P1 V1

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4

Sound waves propagation in air exemplifies an __________ process.

A. Adiabatic

B. Isothermal

C. Isometric

D. None of these

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4

The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is

A. 100,000 kW

B. 160,000 kW

C. 200,000 kW

D. 320,000 kW

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4

The acentric factor of a materical, 'ω', is defined as ω = -log10(Prsat)Tr-1 = 0.7, where, Prsat = reduced vapor pressure, Tr = reduced temperature. The value of acentric factor is always

A. > 2

B. < 1

C. > 1

D. < 3

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4

At normal boiling point, molar entropy of vaporisation is __________ Joule/K°.mole.

A. 72

B. 92

C. 142

D. 192

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4

The relation connecting the fugacities of various components in a solution with one another and to composition at constant temperature and pressure is called the __________ equation.

A. Gibbs-Duhem

B. Van Laar

C. Gibbs-Helmholtz

D. Margules

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4

A Carnot cycle consists of the following steps:

A. Two isothermal and two isentropic

B. Two isobaric and two isothermal

C. Two isochoric and two isobaric

D. Two isothermals and two isochoric

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4

The necessary and sufficient condition for equilibrium between two phases is

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

B. The temperature of each phase should be same

C. The pressure should be same in the two phases

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

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4

Near their critical temperatures, all gases occupy volumes __________ that of the ideal gas.

A. Less than

B. Same as

C. More than

D. Half

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4

The entropy change in a reversible isothermal process, when an ideal gas expands to four times its initial volume is

A. R loge 4

B. R log10 4

C. Cv log10 4

D. Cv loge 4

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4

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

A. Triple point

B. Boiling point

C. Below triple point

D. Always

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4

Pick out the wrong statement.

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

B. Entropy of a system decreases with the evolution of heat

C. Change of internal energy is negative for exothermic reactions

D. The eccentric factor for all materials is always more than one

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4

A cyclic engine exchanges heat with two reservoirs maintained at 100 and 300°C respectively. The maximum work (in J) that can be obtained from 1000 J of heat extracted from the hot reservoir is

A. 349

B. 651

C. 667

D. 1000

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4

Minimum number of phases that exists in a system is 1. Number of chemical species in a colloidal system is

A. 1

B. 2

C. 3

D. 4

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4

First law of thermodynamics deals with the

A. Direction of energy transfer

B. Reversible processes only

C. Irreversible processes only

D. None of these

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4

Which of the following is affected by the temperature?

A. Fugacity

B. Activity co-efficient

C. Free energy

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

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4

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

A. Reversible isothermal volume change

B. Heating of a substance

C. Cooling of a substance

D. Simultaneous heating and expansion of an ideal gas

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4

The difference between isothermal compressibility and adiabatic compressibility for an ideal gas is

A. 0

B. +ve

C. -ve

D.

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4

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

A. Temperature

B. Pressure

C. Composition

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

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4

In any spontaneous process,

A. Only F decreases

B. Only A decreases

C. Both F and A decreases

D. Both F and A increase

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4

What is the degree of freedom for a system comprising liquid water equilibrium with its vapour?

A. 0

B. 1

C. 2

D. 3

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4

Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole. °K

A. 0

B.

C. 50

D. 100

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4

In a turbine, the fluid expands almost

A. Isothermally

B. Isobarically

C. Adiabatically

D. None of these

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4

In an ideal gas mixture, fugacity of a species is equal to its

A. Vapor pressure

B. Partial pressure

C. Chemical potential

D. None of these