Top 350+ Solved Thermodynamics MCQ Questions Answer
Q. Isentropic flow is
a. Irreversible adiabatic flow
b. Ideal fluid flow
c. Change in entropy is zero
d. Frictionless reversible flow
e. Perfect gas flow
Q. The triple point for carbondioxide is at about -56.7 C and about 5 atm, pressure. It means that
a. Mass transfer at triple point is maximum
b. When CO2 is exposed to a below 5 atmosphere pressure only solid and liquid phase exist together
c. Above 56.7 C CO2 exists only as a liquid
d. Below 57.7 C CO2 exists only in liquid form
e. When solid CO2 is exposed to 1 atm pressure it begins to change directly to gas
Q. In a reversible cycle, the entropy of the system
a. Depends on the properties of working substance
b. Decreases
c. Does not change
d. Increases
e. First increases and then decreases
Q. The first law of thermodynamics, for steady flow
a. Accounts for all energy entering and leaving a control volume
b. Is primarily concerned with heat transfer
c. Is restricted in its application to perfect gases
d. Is an energy balance for the specified mass of fluid
e. Is an expression of the conservation of linear momentum
Q. Which of the following is not a characteristic of liquid air?
a. It will cause rubber to become brittle
b. Pulsejet
c. It will freeze mercury and ammonia
d. It has no surface tension
e. It will separate out lead from solder
Q. Which of the following relation does not hold good for a throttling process?
a. dQ = 0
b. dS = 0
c. Pulsejet
d. dH = 0
e. dW = 0
Q. According to Amagat's law
a. the sum of the volume friction is unity
b. there would be no volume change if the components are mixed while holding the temperature and pressure constant
c. all diatomic gases occupy double the volume of monoatomic gases for identical masses
d. None of the above
e. Pulsejet
Q. In the polytropic process pvn = Constant if n = 1 the process is termed as
a. Adiabatic
b. Constant pressure
c. Constant temperature
d. Constant volume
e. Isothermal
Q. Otto cycle consists of the set of processes as
a. Two isentropics and two constant volumes
b. Two isothermal and two constant volume
c. Two isentropics and two constant pressure
d. Two adiabatic and two isothermal
e. Two isothermal and two constant pressure
Q. If the two specific heats of a gas are 0.237 and 0.169 respectively, the volume of 3 kg of air at 27?C under a pressure of 3 ata would be
a. 2.5 cu-m
b. 1 cu-m
c. 0.204 cu-m
d. 1.74 cu-m
e. 1.5 cu-m
Q. Five people must be lifted in an elevator to a distance of 100 m. The work is found to be 341.2 kJ and the gravitational acceleration is 9.75 m/s2. The average mass per person is
a. Pulsejet
b. 72 kg
c. 70 kg
d. 67.5 kg
e. 65 kg
Q. A substance above critical temperature exists as
a. Solid
b. Liquid
c. Gas
d. Unsaturated vapour
e. Any of the above
Q. In the above problem work done is equal to
a. 130 kcal
b. 150 kcal
c. 100 kcal
d. 80 kcal
e. 180 kcal
Q. In a boiler a fusible plug is located at the
a. Pulsejet
b. inlet to stop valve
c. top of superheater
d. bottom of drum
e. bottom of fire tubes