Questions and answers for exam Preparation

MCQs

Laws Of Thermodynamics

Total Questions : 1462 | Page 6 of 147 pages

Question 51. A process, in which the temperature of the working substance remains constant during its expansion or compression, is called

isothermal process
hyperbolic process
adiabatic process
polytropic process

Discuss Question

Answer: Option A. -> isothermal process
Answer: (a).isothermal process

Question 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.

directly
indirectly
Can't say
None of these

Discuss Question

Answer: Option A. -> directly
Answer: (a).directly

Question 53. According to Kelvin-Planck's statement of second law of thermodynamics,

it is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
it is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
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
none of the above

Discuss Question

Answer: Option A. -> it is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
Answer: (a).it is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work

Question 54. All the commercial liquid fuels are derived from natural petroleum (or crude oil).

True
False
Can't say
None of these

Discuss Question

Answer: Option A. -> True
Answer: (a).True

Question 55. A cycle consisting of one constant pressure, one constant volume and two isentropic processes is known as

Carnot cycle
Stirling cycle
Otto cycle
Diesel cycle

Discuss Question

Answer: Option D. -> Diesel cycle
Answer: (d).Diesel cycle

Question 56. The amount of heat required to raise the temperature of the unit mass of gas through one degree at constant volume, is called

specific heat at constant volume
specific heat at constant pressure
kilo Joule
none of these

Discuss Question

Answer: Option A. -> specific heat at constant volume
Answer: (a).specific heat at constant volume

Question 57. The efficiency and work ratio of a simple gas turbine cycle are

low
very low
high
very high

Discuss Question

Answer: Option B. -> very low
Answer: (b).very low

Question 58. There is a loss of heat in an irreversible process.

True
False
Can't say
None of these

Discuss Question

Answer: Option A. -> True
Answer: (a).True

Question 59. For the same compression ratio, the efficiency of Diesel cycle is __________ Otto cycle.

greater than
less than
equal to
None of these

Discuss Question

Answer: Option B. -> less than
Answer: (b).less than

Question 60. The heat supplied to the gaS at constant volume is (where m = Mass of gas, cv = Specific heat at constant volume, cp = Specific heat at constant pressure, T2 - T1 = Rise in temperature, and R = Gas constant)