Top 350+ Solved Thermodynamics MCQ Questions Answer
Q. All of the following cycles consists of two isothermal processes EXCEPT
a. Ericsson cycle
b. Stirling cycle
c. Brayton cycle
d. Carnot cycle
e. Pulsejet
Q. Which of the following introduces irreversibility in the actual Carnot engine operation?
a. Higher operating speeds
b. Losses from working fluid in transit
c. Pulsejet
d. Changes in pressure and temperature during the cycle
e. Friction between moving parts
Q. Which of the following is the best fuel for S.I. engines?
a. Naphthenes
b. Olefins
c. Aromatics
d. Pulsejet
e. Paraffins
Q. The cycle generally used for gas turbines is
a. Brayton cycle
b. Carnot cycle
c. Dual cycle
d. Otto cycle
e. Rankine cycle
Q. The slope of constant pressure line on temperature entropy diagrm is given by
a. 90?
b. T/Cp
c. Cp/T
d. S/T
e. T/S
Q. In automobiles clutch is mounted between
a. Gear box and differential
b. Differential and wheels
c. Engine and flywheel
d. Engine and differential
e. Flywheel and gear box
Q. During an adiabatic process the change in entropy is
a. Positive or Negative
b. Zero
c. Negative
d. Approximately zero
e. Positive
Q. The behaviour of which of the following vapour is closer to that of a gas?
a. Wet vapour
b. Wet and superheated vapours
c. Wet and dry vapour
d. Superheated vapour
e. Dry vapour
Q. The ratio of the rise in temperature of a gas when compressed adiabatically to that when compressed isothermally to the same extent is
a. Depends on the gas
b. Pulsejet
c. less than 1
d. Equal to 1
e. More than 1
Q. In all irreversible processes, the entropy of the system
a. Increases
b. Depends on medium
c. Remains constant
d. Sometimes increases and sometimes decreases
e. Reduces to zero
Q. Which of the following remains constant during an adiabatic process?
a. internal energy
b. enthalpy
c. entropy
d. All of the above
e. Pulsejet
Q. Reduced pressure is
a. dimensionless
b. an index of molecular position of gas
c. always unity
d. Pulsejet
e. always less than atmospheric pressure
Q. In the polytropic process equation pvn = constant, if the value of n is infinitely large the process is termed as
a. Adiabatic
b. Constant volume
c. Isothermal
d. Constant pressure
e. Constant temperature
Q. The ratio of the rise in temperature of a gas when compressed adiabatically to that when compressed isothermally to the same extent is
a. More than 1
b. Less than 1
c. Equal to 1
d. Depends on the gas
e. None of the above
Q. Other factors remaining constant, if the temperature of sink is increased, the efficiency of the Carnot engine will
a. increase or decrease depending upon temperature ratio
b. will not change
c. Pulsejet
d. increase
e. decrease