Top 250+ Solved Engineering Thermodynamics MCQ Questions Answer
Q. The flow through turbine on a Mollier chart isrepresented by
a. a) vertical line
b. b) horizontal line
c. c) curved line convex up
d. d) curved line convex down
Q. The latent enthalpy of vapourisation at criticalpoint is
a. a) zero
b. b) minimum
c. c) maximum
d. d) none of the above
Q. Above critical point, asubstance exists as
a. a) vapour
b. b) liquid
c. c) gas
d. d) supersaturated fluid
Q. Triple point of a pure substance is a point atwhich
a. a) solid & vapour exist together
b. b) solid & liquid exist together
c. c) liquid & vapour exist together
d. d) solid, liquid & vapour phases existtogether
Q. Which of the following cycles is used in thermalpower plants?
a. a) brayton
b. b) carnot
c. c) ericsson
d. d) rankine
Q. In a Carnot engine, when the working substance rejects its heat to sink, the temperature of sink
a. a) remains same
b. b) decrease
c. c) increases
d. d) becomes 0??k
Q. Which of the following is used as a working substance for a Carnotcycle?
a. a) ideal gas
b. b) real gas
c. c) steam
d. d) atmospheric air
Q. During phase transitions like vaporization, melting and sublimation
a. pressure and temperature remains constant
b. volume and entropy changes
c. both of the mentioned
d. none of the mentioned
Q. Which of the following requirement is satisfied by a phase change of the first order?
a. there are changes of volume and entropy
b. the first-order derivative of the gibbs function changes discontinuously
c. both of the mentioned
d. none of the mentioned
Q. The vapour pressure p in kPa at
a. p = 101.325 exp (88/r)(1+t/tb)
b. p = 101.325 exp (88/r)(1+tb/t)
c. p = 101.325 exp (88/r)(1-t/tb)
d. p = 101.325 exp (88/r)(1-tb/t)
Q. According to Trouton’s rule, the ratio of latent heat of vaporization to the boiling point at 1.013 bar is
a. 77 kj/kgmol k
b. 88 kj/kgmol k
c. 99 kj/kgmol k
d. 100 kj/kgmol k
Q. Estimate the freezing temperature of liquid water at a pressure of 30 MPa.
a. -2.2°c
b. 0°c
c. -0.2°c
d. -1.2°c