# Thermodynamics – Section 1

41. The constant pressure, constant volume and constant pvn processes are regarded as irreversible process.

A. True
B. False

Correct Answer: A. True

42. Stirling and Ericsson cycles are

A. reversible cycles
B. irreversible cycles
C. semi-reversible cycles
D. quasi-static cycles

Correct Answer: A. reversible cycles

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

Correct Answer: A. zero

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

Correct Answer: C. thermodynamic cycle

45. An isothermal process is governed by

A. Boyle’s law
B. Charles’ law
C. Gay-Lussac law

Correct Answer: A. Boyle’s law

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

Correct Answer: C. enthalpy

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

Correct Answer: C. 133.3 N/m2

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

Correct Answer: D. 7/3

49. The behavior 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

Correct Answer: D. all of these

50. The universal gas constant of a gas is the product of the molecular mass of the gas and the gas constant.

A. Correct
B. Incorrect

Correct Answer: A. Correct