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4

On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line (∂P/ ∂V)T are related as (where, y = Cp/Cv)

A. (∂P/∂V)S = (∂P/∂V)T

B. (∂P/∂V)S = [(∂P/∂V)T]Y

C. (∂P/∂V)S = y(∂P/∂V)T

D. (∂P/∂V)S = 1/y(∂P/∂V)T

Correct Answer :

C. (∂P/∂V)S = y(∂P/∂V)T


Related Questions

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4

The specific heat of saturated water vapour at 100°C is

A.

B. -ve

C. 0

D. +ve

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4

Boiling of liquid is accompanied with increase in the

A. Vapor pressure

B. Specific Gibbs free energy

C. Specific entropy

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

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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

The value of gas constant 'R' is

A. 1.987 cal/gm mole °K

B. 1.987 BTU/lb. mole °R

C. Both (A) and (B)

D. Neither (A) nor (B)

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4

At equilibrium condition, the chemical potential of a material in different phases in contact with each other is equal. The chemical potential for a real gas (μ) is given by (where, μ = standard chemical potential at unit fugacity (f° = 1 atm.) and the gas behaves ideally.)

A. μ° + RT ln f

B. μ°+ R ln f

C. μ° + T ln f

D. μ° + R/T ln f

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4

Pick out the wrong statement.

A. Minimum number of degree of freedom of a system is zero

B. Degree of freedom of a system containing a gaseous mixture of helium, carbon dioxide and hydrogen is 4

C. For a two phase system in equilibrium made up of four non-reacting chemical species, the number of degrees of freedom is 4

D. Enthalpy and internal energy change is zero during phase change processes like melting, vaporisation and sublimation

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4

The activity of an ideal gas is numerically __________ its pressure.

A. More than

B. Less than

C. Equal to

D. Data insufficient, can't be predicted

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4

The expression, ΔG = nRT. ln(P2/P1), gives the free energy change

A. With pressure changes at constant temperature

B. Under reversible isothermal volume change

C. During heating of an ideal gas

D. During cooling of an ideal gas

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4

Heat pump

A. Accomplishes only space heating in winter

B. Accomplishes only space cooling in summer

C. Accomplishes both (A) and (B)

D. Works on Carnot cycle

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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

Joule-Thomson Co-efficient at any point on the inversion curve is

A.

B. +ve

C. 0

D. -ve

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4

Pick out the undesirable property for a good refrigerant.

A. High thermal conductivity

B. Low freezing point

C. Large latent heat of vaporisation

D. High viscosity

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4

The ammonia synthesis reaction represented by N2 + 3H2 2NH3; ΔH = - 22.4 kcal, is

A. Endothermic

B. Exothermic

C. Isothermal

D. Adiabatic

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4

First law of thermodynamics is mathematically stated as

A. dQ = dE + dW

B. dQ = dE - dW

C. dE = dQ + dW

D. dW = dQ + dE

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4

Which of the following is not a common refrigerant?

A. Freon-12

B. Ethylene

C. Ammonia

D. Carbon dioxide

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4

At triple point (for one component system), vapour pressure of solid as compared to that of liquid will be

A. More

B. Less

C. Same

D. More or less; depending on the system

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4

In the ammonia synthesis reaction, N2 + 3H2 2NH3 + 22.4 kcal, the formation of NH3 will be favoured by

A. High temperature

B. Low pressure

C. Low temperature only

D. Both low temperature and high pressure

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4

Thermal efficiency of a Carnot engine can approach 100%, only when the temperature of the

A. Cold reservoir approaches zero

B. Hot reservoir approaches infinity

C. Either (A) or (B)

D. Neither (A) nor (B)

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4

4 kg moles of an ideal gas expands in vacuum spontaneously. The work done is

A. 4 J

B.

C. 0

D. 8 J

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4

A closed system is cooled reversibly from 100°C to 50°C. If no work is done on the system

A. its internal energy (U) decreases and its entropy (S) increases

B. U and S both decreases

C. U decreases but S is constant

D. U is constant but S decreases

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4

A system undergoes a change from a given initial state to a given final state either by an irreversible process or by a reversible process, then (where, Δ S1 and Δ SR are the entropy changes of the system for the irreversible and reversible processes respectively)

A. Δ S1 is always < Δ SR

B. Δ S1 is sometimes > Δ SR

C. Δ S1 is always > Δ SR

D. Δ S1 is always = Δ SR

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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 the reaction, C + O2 → CO2; ΔH = - 94 kcal. What is the heat content (enthalpy) of O2?

A. -94 kcal

B. > -94 kcal

C. < - 94 kcal

D. Zero

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4

If atmospheric temperature and dew point are nearly equal, then the relative humidity is

A. Zero

B. 50%

C. Almost 100%

D. unpredictable

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4

Which of the following identities can be most easily used to verify steam table data for superheated steam?

A. (∂T/∂V)S = (∂p/∂S)V

B. (∂T/∂P)S = (∂V/∂S)P

C. (∂P/∂T)V = (∂S/∂V)T

D. (∂V/∂T)P = -(∂S/∂P)T

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4

A large iceberg melts at the base, but not at the top, because of the reason that

A. Ice at the base contains impurities which lowers its melting point

B. Due to the high pressure at the base, its melting point reduces

C. The iceberg remains in a warmer condition at the base

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

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4

The chemical potential for a pure substance is __________ its partial molal free energy.

A. More than

B. Less than

C. Equal to

D. Not related to

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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

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

In the reaction; N2 + O2 2NO, increasing the pressure will result in

A. Shifting the equilibrium towards right

B. Shifting the equilibrium towards left

C. No change in equilibrium condition

D. None of these