Top 250+ Solved Engineering Thermodynamics MCQ Questions Answer
Q. For storing a gas which one of the following types of compression will beideal
a. a) constant volume
b. b) polytropic
c. c) adiabatic
d. d) isothermal
Q. A process which can be stopped at any stage & reversed so that the system & the surroundings are exactly restored to their initial states is known as
a. a) thermodynamic process
b. b) irreversible process
c. c) reversible process
d. d) isothermal process
Q. Which of the following is a reversibleprocess?
a. a) throttling
b. b) combustion
c. c) free expansion
d. d) extension &compression of a spring
Q. Leaking of air from a punctured tube is anexample of
a. a) isothermal expansion
b. b) adiabatic expansion
c. c) throttling
d. d) constant pressureexpansion
Q. To convert volumetric analysis to gravimetric analysis, the relative volume of each constituent of the flue gases is
a. a) divided by its specific weight
b. b) multiplied by its density
c. c) multiplied by its molecular weight
d. d) divided by its molecular weight
Q. a heat engine receives heat at the rate of 1500 kJ/min.& gives an output of 8.2 kW. Its thermal efficiency is equal to
a. a) 20.5 %
b. b) 30.2%
c. c) 32.8%
d. d) 44.6%
Q. An inventor claims that a new heat cycle will develop 0.4 kW for a heat addition of32.5 kJ/mm. The temperature of heat source is 1990 K & that of sink is 850K. Is his claim true?
a. a) true
b. b) false
c. c) either of the above
d. d) unpredictable
Q. Consider the following statements: The definition of1. temperature is due to zeroth law of thermodynamics2. entropy is due to first law of thermodynamics3. internal energy is due to second law of thermodynamics4. reversibility is due to Kelvin-Planck's ststement of these statements
a. a) 1,2 & 3 are correct
b. b) 1,3 & 4 are correct
c. c) 1 alone is correct
d. d) 2 alone is correct
Q. A heat engine is supplied with 250 kJ/s of heat at a constant fixed temperature of 227°C. The heat is rejected at 27°C. The cycle is reversible, if the amount of heat rejected is
a. a) 273 kj/s
b. b) 200 kj/s
c. c) 180 kj/s
d. d) 150 kj/s
Q. If a heat enine gives an output of 3 kW when the input is 10,000 J/s, then the thermal efficiency of the engine will be
a. a) 20%
b. b) 30%
c. c) 70%
d. d) 76.7%
Q. The fundamental unit of enthalpy is
a. a) mlt ????
b. b) ml??t????
c. c) ml??t ????
d. d) ml??t ????
Q. In a cyclic heat engine operating between a source temperature of 600°C & a sink temperature of 20°C, the least rate of heat rejection per kW net output of theengine is
a. a) 0.460 kw
b. b) 0.505 kw
c. c) 0.588 kw
d. d) 0.650 kw
Q. In a reversible cycle, the source temperature is 227°C & the sink temperature is 27°C. The maximum available work for a heat input of 100 kJwill be
a. a) 100 kj
b. b) 60 kj
c. c) 40 kj
d. d) 88 kj