thermodynamics MCQs – Page 4

Practise focused thermodynamics questions with marked answers for exam preparation and subject revision.

thermodynamics Mcqs
61. In an isothermal process, the internal energy________________?
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A. first decreases and then increases

B. increases

C. decreases

D. remains constant

E. first increases and then decreases

62. Work done is zero for the following process_________________?
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A. free expansion

B. none of the above

C. all Of the above

D. throttling

E. constant volume

63. Which of the following can be regarded as gas so that gas laws could be applicable, within the commonly encountered temperature limits ?
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A. steam vapours, H2, C02

B. 02, N2, H2, air

C. 02, N2, steam, C02

D. S02, NH3, C02, moisture

E. Oz, N2, water vapour

64. The first law of thermodynamics is the law of_________________?
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A. conservation of energy

B. conservation of momentum

C. conservation of mass

D. conservation of heat

E. conservation of temperature

65. Compressed air coming out from a punctured football___________________?
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A. attains atmospheric temperature

B. may become hotter or cooler depend-ing upon the humidity of the surrounding air

C. becomes hotter

D. becomes cooler1

E. remains at the same temperature

66. First law of thermodynamics furnishes the relationship between______________________?
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A. various thermodynamic processes

B. heat, work and properties of the system

C. heat and internal energy

D. various properties of the system

E. heat and work

67. General gas equation is____________________?
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A. PV=KiRT

B. PV=nRT

C. Cp-Cv = Wj

D. PV = C

E. PV=mRT
68. The value of n = 1 in the poly tropic process indicates it to be __________________?
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A. irreversible process

B. isothermal process

C. reversible process

D. adiabatic process

E. free expansion process

69. An isolated system is one in which_____________________?
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A. mass does not cross boundaries of the system, though energy may do so

B. neither mass nor energy crosses the boundaries of the system

C. both energy and mass cross the boundaries of the system

D. mass crosses the boundary but not the energy

E. thermodynamic reactions do not occur

70. If a fluid expands suddenly into vacuum through an orifice of large dimension, then such a process is called___________________?
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A. free expansion

B. adiabatic expansion

C. throttling

D. parabolic expansion

E. hyperbolic expansion

71. One watt is equal to__________________?
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A. 1 N/mt

B. 1 kNm/hr

C. 1 Nm/s

D. 1 Nm/hr

E. 1 kNm/mt

72. Characteristic gas constant of a gas is equal to______________________?
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A. Cv/Cp

B. Cp x Cv

C. C/Cv

D. Cp Cv

E. Cp + Cv

73. Which of the following is an irreversible cycle_____________________?
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A. all of the above

B. carnot

C. ericsson

D. none of the above

E. Stirling

74. The specific heat of air increases with increase in __________________?
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A. temperature

B. pressure

C. both pressure and temperature

D. variation of its constituents

E. air flow

75. Change in enthalpy of a system is the heat supplied at___________________?
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A. constant entropy

B. constant pressure

C. constant volume

D. N.T.P. condition

E. constant temperature

76. A diathermic wall is one which____________________?
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A. permits thermal interaction

B. discourages thermal interaction

C. does not exist

D. prevents thermal interaction

E. encourages thermal interaction

77. The behaviour of gases can be fully determined by___________________?
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A. 3 laws

B. 2 laws

C. 4 laws

D. 1 law

78. Temperature of a gas is produced due to________________?
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A. kinetic energy of molecules

B. its heating value

C. repulsion of molecules

D. surface tension of molecules

E. attraction of molecules

79. Which of the following quantities is not the property of the system__________________?
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A. pressure

B. specific volume

C. density

D. temperature

E. heat
80. 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_______________?
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A. 100 xlOO5 joules

B. 10 xlO5 kilo joules

C. lxlO5 joules

D. 10xl04kiojoules

E. 10 xlO5 joules