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In the equation, PVn = constant, if the value of n = 1, then it represents a reversible __________ process.

A. Isothermal

B. Isobaric

C. Polytropic

D. Adiabatic

Correct Answer :

A. Isothermal


Related Questions

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Which of the following represents the Virial equation of state?

A. T = [RT/(V- b)] - [a/√T. V(V + b)]

B. PV/RT = 1 + (B/V) + (C/V2) + ……

C. n1u2 + μ2μ1 = 0

D. None of these

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4

Which of the following equations is used for the prediction of activity co-efficient from experiments?

A. Van Laar equation

B. Margules equation

C. Wilson's equation

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

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4

Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is

A. Positive

B. Negative

C. Zero

D. Infinity

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High pressure steam is expanded adiabatically and reversibly through a well insulated turbine, which produces some shaft work. If the enthalpy change and entropy change across the turbine are represented by ΔH and ΔS respectively for this process:

A. Δ H = 0 and ΔS = 0

B. Δ H ≠ 0 and ΔS = 0

C. Δ H ≠ 0 and ΔS ≠ 0

D. Δ H = 0 and ΔS ≠ 0

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Adiabatic compression of a saturated water vapour makes it

A. Supersaturated

B. Superheated

C. Both (A) and (B)

D. Neither (A) nor (B)

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In an ideal solution, the activity of a component equals its

A. Mole fraction

B. Fugacity at the same temperature and pressure

C. Partial pressure

D. None of these

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The chemical potential of a component (μi) of a phase is the amount by which its capacity for doing all work, barring work of expansion is increased per unit amount of substance added for an infinitesimal addition at constant temperature and pressure. It is given by

A. (∂E/∂ni)S, v, nj

B. (∂G/∂ni)T, P, nj = (∂A/∂ni) T, v, nj

C. (∂H/∂ni)S, P, nj

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

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The melting point of paraffin wax (which contracts on solidification) __________ with pressure rise.

A. Increases

B. Decreases

C. Remains unchanged

D. Decreases linearly

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The work done in isothermal compression compared to that in adiabatic compression will be

A. Less

B. More

C. Same

D. More or less depending upon the extent of work done

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4

For a reversible 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

Pick out the correct statement:

A. In an isothermal system, irreversible work is more than reversible work

B. Under reversible conditions, the adiabatic work is less than isothermal work

C. Heat, work, enthalpy and entropy are all 'state functions'

D. Matter and energy cannot be exchanged with the surroundings in a closed system

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Any substance above its critical temperature exists as

A. Saturated vapour

B. Solid

C. Gas

D. Liquid

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The effect of changing the evaporator temperature on COP as compared to that of changing the condenser temperature (in vapour compression refrigeration system) is

A. Less pronounced

B. More pronounced

C. Equal

D. Data insufficient, can't be predicted

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Melting of ice exemplifies a/an

A. Adiabatic process

B. Endothermic reaction

C. Exothermic reaction

D. Process involving a chemical reaction

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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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PVy = constant, holds good for an isentropic process, which is

A. Reversible and isothermal

B. Isothermal and irreversible

C. Reversible and adiabatic

D. Adiabatic and irreversible

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Pick out the wrong statement

A. Phase rule variables are intensive properties

B. Heat and work are both state function

C. The work done by expansion of a gas in vacuum is zero

D. CP and CV are state function

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4

A refrigerator may be termed as a

A. Heat pump

B. Heat engine

C. Carnot engine

D. None of these

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Which of the following is an extensive property of a system?

A. Heat capacity

B. Molal heat capacity

C. Pressure

D. Concentration

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(∂T/∂P)H is the mathematical expression for

A. Specific heat at constant pressure (Cp)

B. Specific heat at constant volume (Cv)

C. Joule-Thompson co-efficient

D. None of these

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An isolated system can exchange __________ with its surroundings.

A. Matter

B. Energy

C. Neither matter nor energy

D. Both matter and energy

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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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What happens in a reversible adiabatic compression?

A. Heating occurs

B. Cooling occurs

C. Pressure is constant

D. Temperature is constant

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The first law of thermodynamics is a restatement of the law of conservation of

A. Mass

B. Energy

C. Momentum

D. None of these

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In which of the following reaction equilibrium, the value of equilibrium constant Kp will be more than is Kc?

A. 2HI H2 + I2

B. N2O4 2NO2

C. 2SO2 + O2 2SO3

D. None of these

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Joule-Thomson co-efficient which is defined as, η = (∂T/∂P)H = 1/Cp (∂H/∂T)P, changes sign at a temperature known as inversion temperature. The value of Joule-Thomson co-efficient at inversion temperature is

A. 0

B.

C. +ve

D. -ve

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The work done in an adiabatic change in a particular gas depends upon changes in the __________ only.

A. Temperature

B. Specific heat

C. Volume

D. Pressure

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The compressibility factor for an ideal gas is 1. Its value for any other real gas is

A. 1

B. < 1

C. > 1

D. Either (B) or (C), depends on the nature of the gas

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At a given temperature, the volume of a gas dissolved in a solvent __________ with increase in pressure.

A. Increases

B. Decreases

C. Remains unchanged

D. May increase or decrease; depends on the gas

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Generation of heat by friction is an example of a/an __________ change.

A. Isothermal

B. Irreversible

C. Adiabatic

D. Reversible