71. The value of the product of molecular weight and the gas characteristic constant for all the gases in M.K.S. unit is

A.29.27 kgf-m/mol°K

B.8314 kgf-m/mol°K

C.848 kgf-m/mol°K

D.427 kgf-m/mol°K

72. Universal gas constant is defined as equal to product of the molecular weight of the gas and

A.Specific heat at constant pressure

B.Specific heat at constant volume

C.Ratio of two specific heats

D.Gas constant

73. For which of the following substances, the internal energy and enthalpy are the functions of temperature only

A.Any gas

B.Saturated steam

C.Water

D.Perfect gas

74. In a free expansion process

A.Work done is zero

B.Heat transfer is zero

C.Both (A) and (B) above

D.Work done is zero but heat increases

75. The value of the product of molecular weight and the gas characteristic constant for all the gases in S.I. units is

A.29.27 J/kmol °K

B.83.14 J/kmol °K

C.848 J/kmol °K

D.All J/kmol °K

76. If a gas vapour is allowed to expand through a very minute aperture, then such a process is known as

A.Free expansion

B.Hyperbolic expansion

C.Throttling

D.Parabolic expansion

77. If a fluid expands suddenly into vacuum through an orifice of large dimension, then such a process is called

A.Free expansion

B.Hyperbolic expansion

C.Adiabatic expansion

D.Parabolic expansion

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