SECTION-2

##### Q71. The efficiency of the Carnot cycle may be increased by

(a) increasing the highest temperature
(b) decreasing the lowest temperature
(c) increasing the lowest temperature
(d) both (a) and (b).

Ans:(d) both (a) and (b).

(a) 80%
(b) 70%
(c) 66.67%
(d) 50%.

Ans:(c) 66.67%

##### Q73. The Carnot cycle cannot be realised in actual practice due to

(a) very high pressure developed in the cylinder
(b) high volume ratios in the cylinder
(c) both (a) and (b)
(d) none of the above.

Ans:(c) both (a) and (b)

##### Q74. The ideal cycle for comparing the performance of steam plants is

(a) Carnot cycle
(b) Rankine cycle
(c) Otto cycle
(d) Stirling cycle.

Ans:(b) Rankine cycle

##### Q75. The relationship between entropy, enthalpy and work is given by

(a) Tds = dH + Vdp
(b) dH = Vdp – Tds
(c) Tds = dH – Vdp
(d) Vdp =dH/Tds

Ans:(c) Tds = dH – Vdp

##### Q76. A gas follows the law pVn = C. If the value of n = 1, the process is known as

(b) isothermal
(c) isentropic
(d) polytropic.

Ans:(b) isothermal

##### Q77. The law which states that the volume of a given mass of a perfect gas varies directly as its absolute temperature, when the absolute pressure remains constant is known as

(a) Charle’s law
(b) Boyle’s law
(c) Gay-Lussac law

Ans:(a) Charle’s law

##### Q78. The law which states that the equal volumes of all gases, at the same temperature and pressure, contain equal number of molecules is known as

(a) Charle’s law
(b) Boyle’s law
(c) Gay-Lussac law

##### Q79. The law which states that the absolute pressure of a perfect gas varies directly with the absolute temperature volume is kept constant is known as

(a) Charle’s law
(b) Boyle’s law
(c) Gay-Lussac law

Ans:(c) Gay-Lussac law

##### Q80. The law which states that change of internal energy of a perfect gas is directly proportional to the change of temperature, is known as

(a) Boyle’s law
(b) Charle’s law
(c) Joule’s law

Ans:(c) Joule’s law

1      2      3          5          7      8

DEAR READERS IF YOU FIND ANY ERROR/TYPING MISTAKE PLEASE LET ME KNOW IN THE COMMENT SECTIONS OR E-MAIL: [email protected]

##### Read More Sections of Thermodynamics Objective Questions

Each section contains maximum 80 Questions. To practice more questions visit other sections.

Thermodynamics Objective Questions – Section-1

Thermodynamics Objective Questions – Section-2

Thermodynamics Objective Questions – Section-3

Thermodynamics Objective Questions – Section-4