Top 250+ Solved Engineering Thermodynamics MCQ Questions Answer
Q. An engine receives 15152 J/s of heat & produces 5 KW of power. The efficiencyof the engine is
a. 25%
b. 27.5%
c. 30%
d. 33%
Q. Choose the correct statement
a. a) pressure, temp. & entropy are extensiveproperties
b. b) pressure, temp. & entropy are intensiveproperties
c. c) pressure, volume & temp. are extensive properties
d. d) volume & entropy are extensive properties
Q. The second law of thermodynamicsdefines
a. a) heat
b. b) enthalpy
c. c) internal energy
d. d) entropy
Q. Which of the following processes is essentially irreversible
a. a) isothermal
b. b) adiabatic
c. c) isentropic
d. d) thrittling
Q. A thermodynamic cycle operates between 400 K. & 290 K. 500 MJ/s of heat is added to the working substance.The power generated is
a. a) 290 mw
b. b) 290 mj
c. c) 137.5 mw
d. d) 137.5 mj
Q. A reversible engine performing as engine has efficiency of 62.5%. If it is reversed to work as refrigerator its COP will be
a. a) 60%
b. b) 62.5%
c. c) 65%
d. d) 37.5%
Q. A reversible engine performing as refrigerator has COP=33%. If the same machine operates as engine, its efficiencywill be
a. a) 67%
b. b) 33%
c. c) 75%
d. d) 37.5%
Q. The amount of heat absorbed by asystem at lower temperature is
a. a) coeff. of performance
b. b) efficiency
c. c) work supplied
d. d) refrigerating effect
Q. In an ideal gas the partial pressure of a component is
a. a) inversely proportional to the square of the molefraction
b. b) directly proportional to the mole fraction
c. c) inversely proportional to the mole fraction
d. d) equal to the mole fraction
Q. The value of the univesal gas constant is
a. a) 0.314 j/kg k
b. b) 83.14 kj/kg k
c. c) 848 kj/kg k
d. d) 8.314 kj/kg k
Q. Choose the correct answer
a. a) a perfect gas does not obey the law pv=rt
b. b) a perfect gas obeys the law pv=rt & has constant specific heat
c. c) a perfect gas obeys the law pv=rt but have variable specific heat capacities
d. d) all of the above
Q. Boyle's law states that, when tempearture is constant, the volume of agiven mass of a perfect gas
a. a) varies directly as the absolute pressure
b. b) varies inversely as the absolute pressure
c. c) varies as square of the absolute pressue
d. d) does not vary with the absolute pressure