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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

Correct Answer :

A. Direction of energy transfer


Related Questions

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4

Pick out the extensive property out of the following.

A. Surface tension

B. Free energy

C. Specific heat

D. Refractive index

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4

Which of the following is not an intensive property?

A. Chemical potential

B. Surface tension

C. Heat capacity

D. None of these

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4

Pick out the Clausius-Clapeyron equation from the following:

A. dP/dT = ΔH/TΔV

B. ln P = - (ΔH/RT) + constant

C. ΔF = ΔH + T [∂(ΔF)/∂T]P

D. None of these

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4

Enthalpy of a gas depends upon its

A. Temperature

B. Mass

C. Volume

D. Pressure

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4

Entropy is a/an

A. State function

B. Macroscopic property

C. Extensive property

D. None of these

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4

A refrigeration cycle is a reversed heat engine. Which of the following has the maximum value of the co-efficient of performance (COP) for a given refrigeration effect?

A. Vapor compression cycle using expansion valve

B. Air refrigeration cycle

C. Vapor compression cycle using expansion engine

D. Carnot refrigeration cycle

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4

In case of a close thermodynamic system, there is __________ across the boundaries.

A. No heat and mass transfer

B. No mass transfer but heat transfer

C. Mass and energy transfer

D. None of these

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4

At the critical point of a substance

A. The surface tension vanishes

B. Liquid and vapour have the same density

C. There is no distinction between liquid and vapour phases

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

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4

Gibbs free energy per mole for a pure substance is equal to the

A. Latent heat of vaporisation

B. Chemical potential

C. Molal boiling point

D. Heat capacity

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4

Pick out the wrong statement.

A. Enthalpies of all elements in their standard states are assumed to be zero

B. Combustion reactions are never endothermic in nature

C. Heat of reaction at constant volume is equal to the change in internal energy

D. Clausius-Clapeyron equation is not applicable to melting process

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4

For an isothermal process, the internal energy of a gas

A. Increases

B. Decreases

C. Remains unchanged

D. Data insufficient, can't be predicted

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4

The four properties of a system viz. P, V, T, S are related by __________ equation.

A. Gibbs-Duhem

B. Gibbs-Helmholtz

C. Maxwell's

D. None of these

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4

An isentropic process is carried out at constant

A. Volume

B. Pressure

C. Temperature

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

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4

Partial molar free energy of an element A in solution is same as its

A. Chemical potential

B. Activity

C. Fugacity

D. Activity co-efficient

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4

Heat is added at constant temperature in an ideal __________ cycle.

A. Stirling

B. Brayton

C. Rankine

D. None of these

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4

As the temperature is lowered towards the absolute zero, the value of the quantity (∂ΔF/∂T) approaches

A. Zero

B. Unity

C. Infinity

D. None of these

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4

Helmholtz free energy (A) is defined as

A. A = H - TS

B. A = E - TS

C. A = H + TS

D. None of these

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4

Cv is given by

A. (∂E/∂T)V

B. (∂E/∂V)T

C. (∂E/∂P)V

D. (∂V/∂T)P

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4

At __________ point, all the three phases (i.e. solid, liquid and gas) co-exist.

A. Eutectic

B. Triple

C. Plait

D. Critical

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4

Which of the following exemplifies an adiabatic process?

A. Melting of ice

B. Condensation of alcohol vapor

C. Sudden bursting of a cycle tube

D. Evaporation of water

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4

Free energy changes for two reaction mechanism 'X' and 'Y are respectively - 15 and - 5 units. It implies that X is

A. Slower than Y

B. Faster than Y

C. Three times slower than Y

D. Three times faster than Y

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4

Consider the reaction, C + O2 CO2; ΔH = - 94 kcal. What will be the value of ΔH for the reaction CO2 → C + O2?

A. -94 kcal

B. +94 kcal

C. > 94 kcal

D. < -94 kcal

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4

Entropy of a substance remains constant during a/an __________ change.

A. Reversible isothermal

B. Irreversible isothermal

C. Reversible adiabatic

D. None of these

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4

For an irreversible process involving only pressure-volume work

A. (dF)T, p <0

B. (dF)T, p = 0

C. (dF)T, p > 0

D. (dA)T, v >0

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4

For an isothermal reversible compression of an ideal gas

A. Only ΔE = 0

B. Only ΔH =0

C. ΔE = ΔH = 0

D. dQ = dE

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4

COP of a refrigerator drawing 1 kW of power per ton of refrigeration is about

A. 0.5

B. 3.5

C. 4.5

D. 8.5

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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

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4

The efficiency of an Otto engine compared to that of a diesel engine, for the same compression ratio will be

A. More

B. Less

C. Same

D. Data insufficient to predict

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4

The thermodynamic law, PVy = constant, is not applicable in case of

A. Ideal compression of air

B. Free expansion of an ideal gas

C. Adiabatic expansion of steam in a turbine

D. Adiabatic compression of a perfect gas

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4

Pick out the wrong statement.

A. A closed system does not permit exchange of mass with its surroundings but may permit exchange of energy.

B. An open system permits exchange of both mass and energy with its surroundings

C. The term microstate is used to characterise an individual, whereas macro-state is used to designate a group of micro-states with common characteristics

D. None of the above