Thermodynamics MCQ
SET-3
41. The constant pressure, constant volume and constant pvn processes are regarded as irreversible process.
- A. True
- B. False
Answer: A
42. Stirling and Ericsson cycles are
- A. reversible cycles
- B. irreversible cycles
- C. semi-reversible cycles
- D. quasi-static cycles
Answer: A
43. When cut-off ratio is __________ the efficiency of Diesel cycle approaches to Otto cycle efficiency.
- A. zero
- B. 1/5
- C. 4/5
- D. 1
Answer: A
44. A series of operations, which takes place in a certain order and restore the initial conditions at the end, is known as
- A. reversible cycle
- B. irreversible cycle
- C. thermodynamic cycle
- D. none of these
Answer: C
45. An isothermal process is governed by
- A. Boyle’s law
- B. Charles’ law
- C. Gay-Lussac law
- D. Avogadro’s law
Answer: A
46. The sum of internal energy (U) and the product of pressure and volume (p.v) is known as
- A. workdone
- B. entropy
- C. enthalpy
- D. none of these
Answer: C
47. The value of 1 mm of Hg is equal to
- A. 1.333 N/m2
- B. 13.33 N/m2
- C. 133.3 N/m2
- D. 1333 N/m2
Answer: C
48. One kg of carbon requires 4/3 kg of oxygen and produces __________ kg of carbon monoxide gas.
- A. 8/3
- B. 11/3
- C. 11/7
- D. 7/3
Answer: D
49. The behaviour of a perfect gas, undergoing any change in the variables which control physical properties, is governed by
- A. Boyle’s law
- B. Charles’ law
- C. Gay-Lussac law
- D. all of these
Answer: D
50. The universal gas constant of a gas is the product of molecular mass of the gas and the gas constant.
- A. Correct
- B. Incorrect
Answer: A
51. According to Kelvin-Planck’s statement of second law of thermodynamics,
- A. it is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
- B. it is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
- C. it is impossible to construct a device which operates in a cyclic process and produces no effect other than the transfer of heat from a cold body to a hot body
- D. none of the above
Answer: A
52. According to Gay-Lussac law, the absolute pressure of a given mass of a perfect gas varies __________ as its absolute temperature, when the volume remains constant.
- A. directly
- B. indirectly
Answer: A
53. According to Avogadro’s law
- A. the product of the gas constant and the molecular mass of an ideal gas is constant
- B. the sum of partial pressure of the mixture of two gases is sum of the two
- C. equal volumes of all gases, at the same temperature and pressure, contain equal number of molecules
- D. all of the above
Answer: C
54. A process, in which the temperature of the working substance remains constant during its expansion or compression, is called
- A. isothermal process
- B. hyperbolic process
- C. adiabatic process
- D. polytropic process
Answer: A
55. Which of the following gas has a minimum molecular mass?
- A. Oxygen
- B. Nitrogen
- C. Hydrogen
- D. Methane
Answer: C
56. The total energy of a molecule is shared equally by the various degrees of freedom possessed by it. This law is known as
- A. law of equipartition of energy
- B. law of conservation of energy
- C. law of degradation of energy
- D. none of these
Answer: A
57. The thermodynamic property of a system is said to be an intensive property whose value for the entire system __________ the sum of their value for the individual parts of the system.
- A. is equal to
- B. is not equal to
Answer: B
58. The absolute pressure of a given mass of a perfect gas varies inversely as its volume, when the temperature remains constant. This statement is known as Charles’ law.
- A. Yes
- B. No
Answer: B
59. The fuel mostly used in steam boilers is
- A. brown coal
- B. peat
- C. coking bituminous coal
- D. non-coking bituminous coal
Answer: D
60. The efficiency of Joule cycle is
- A. greater than Carnot cycle
- B. less than Carnot cycle
- C. equal to Carnot cycle
- D. none of these
Answer: B