51. Which of the following items is not a path function
(a) heat
(b) work
(c) kinetic energy
(d) vdp
(e) thermal conductivity
Ans: e
52. Work done in an adiabatic process between a given pair of end states depends on
(a) the end states only
(b) particular adiabatic process
(c) the value of index n
(d) the value of heat transferred
(e) mass of the system
Ans: a
53. Heat and work are
(a) point functions
(b) system properties
(c) path functions
(d) intensive properties
(e) extensive properties
Ans: c
54. Which of the following parameters is constant for a mole for most of the gases at a given temperature and pressure
(a) enthalpy
(b) volume
(c) mass
(d) entropy
(e) specific volume
Ans: b
55. The value of n = 1 in the poly tropic process indicates it to be
(a) reversible process
(b) isothermal process
(c) adiabatic process
(d) irreversible process
(e) free expansion process
Ans: b
56. Solids and liquids have
(a) one value of specific heat (ft) two values of specific heat
(c) three values of specific heat
(d) no value of specific heat
(e) one value under some conditions and two values under other conditions
Ans: a
57. A perfect gas at 27°C is heated at constant pressure till its volume is double. The final temperature is
(a) 54°C
(b) 327°C
(c) 108°C
(d) 654°C
(e) 600°C
Ans: b
58. Curve A in Fig. 1.1 compared to curves B and C shows the following type of expansion
(a) pV”=C
(b) isothermal
(c) adiabatic
(d) free expansion
(e) throttling
Ans: b
59. If value of n is infinitely large in a poly tropic process pV” = C, then the process is known as constant
(a) volume
(b) pressure
(c) temperature
(d) enthalpy
(e) entropy
Ans: a
60. The index of compression n tends to reach ratio of specific heats y when
(a) flow is uniform and steady
(b) process is isentropic
(c) process is isothermal
(d) process is isentropic and specific heat does not change with temperature
(e) process is isentropic and specific heat changes with temperature
Ans: d
61. Change in enthalpy of a system is the heat supplied at
(a) constant pressure
(b) constant temperature
(c) constant volume
(d) constant entropy
(e) N.T.P. condition
Ans: a
62. The term N.T.P. stands for
(a) nominal temperature and pressure
(b) natural temperature and pressure
(c) normal temperature and pressure
(d) normal thermodynamic practice
(e) normal thermodynamic pressure
Ans: c
63. A heat exchange process in which the product of pressure and volume remains constant is known as
(a) heat exchange process
(b) throttling process
(c) is entropic process
(d) adiabatic process
(e) hyperbolic process
Ans: e
64. In an isothermal process, the internal energy of gas molecules
(a) increases
(b) decreases
(c) remains constant
(d) may increase/decrease depending on the properties of gas
(e) shows unpredictable behavior
Ans: c
65. Zeroth law of thermodynamics
(a) deals with conversion of mass and energy
(b) deals with reversibility and irreversibility of process
(c) states that if two systems are both in equilibrium with a third system, they are in thermal equilibrium with each other
(d) deals with heat engines
(e) does not exist
Ans: c
66. If a certain amount of dry ice is mixed with same amount of water at 80°C, the final temperature of mixture will be
(a) 80°C
(b) 0°C
(c) 40°C
(d) 20°C
(e) 60°C
Ans: b
67. The basis for measuring thermodynamic property of temperature is given by
(a) zeroth law of thermodynamics
(b) first law of thermodynamics
(c) second law of thermodynamics
(d) third law of thermodynamics
(e) Avogadro’s hypothesis
Ans: a
68. One watt is equal to
(a) 1 Nm/s
(b) 1 N/mt
(c) 1 Nm/hr
(d) 1 kNm/hr
(e) 1 kNm/mt
Ans: a
69. Work done is zero for the following process
(a) constant volume
(b) free expansion
(c) throttling
(d) all Of the above
(e) none of the above
Ans: d
70. For which of the following substances, the gas laws can be used with minimum error
(a) dry steam
(b) wet steam
(c) saturated steam
(d) superheated steam
(e) steam at atmospheric pressure
Ans: d
71. In a non-flow reversible process for which p = (- 3V+ 15) x 105N/m2,V changes from 1 m to 2 m3. The work done will be about
(a) 100 xlOO5 joules
(b) lxlO5 joules
(c) 10 xlO5 joules
(d) 10 xlO5 kilo joules
(e) 10xl04ki\ojoules
Ans: c
72. 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 kgfm/mol°K
(b) 8314kgfm/mol°K
(c) 848kgfm/mol°K
(d) 427kgfm/mol°K
(e) 735 kgfm/mol°K
Ans: c
73. On volume basis, air contains following parts of oxygen
(a) 21
(b) 23
(c) 25
(d) 77
(e) 79
Ans: a
74. 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
(e) unity
Ans: d
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) 83.14J/kmol°K
(c) 848J/kmol°K
(d) All J/kmol °K
(e) 735 J/kmol °K
Ans: b