Top 350+ Solved Thermodynamics MCQ Questions Answer
Q. One of the most efficient engines ever developed operates between 2100 k and 700 k. Its actual efficiency is 40%. What percentage of its maximum possible efficiency is this?
a. 40%
b. 33.30%
c. 60%
d. Pulsejet
e. 66.67%
Q. For any reversible process, the change in entropy of the system and surroundings is
a. Negative
b. Zero
c. Unity
d. Infinite
e. Positive
Q. If all the variables of a steam are in-dependent of time it is said to be in
a. Unsteady flow
b. Uniform flow
c. Steady flow
d. Closed flow
e. Constant flow
Q. A system comprising a single phase is called a
a. Open system
b. Isolated system
c. Closed system
d. Homogeneous system
e. Heterogeneous system
Q. An open system
a. Is a specified region where transfers of energy and/or mass take place
b. Is a region of constant mass and only energy is allowed to cross the boundaries
c. Cannot transfer either energy or mass to or from the surroundings
d. Has a mass transfer across its boundaries, and the mass within the system is not necessarily constant
e. None of the above
Q. In the regenerative cycle
a. Power is generated in two stages
b. Part of the steam is withdrawn from the turbine and is utilised in heating the exhaust steam
c. Steam is reheated after expansion and again used
d. Part of the steam is withdrawn from the turbine and is used in heating the steam being supplied to the turbine
e. Part of the steam is withdrawn from the turbine and is used in heating the feed water
Q. Which of the following is a path function quantity?
a. Work done
b. Pressure
c. Pulsejet
d. Temperature
e. Enthalpy
Q. An ordinary mercury thermometer can be used for temperatures about
a. 200?C
b. 400?C
c. 300?C
d. 100?C
e. 500?C
Q. Triple point
a. Occurs in sublimation
b. Occurs in a mixture of two or more gases
c. Is the range of temperature within which three constituents simultaneously change phase
d. Is that point where three phases solid, liquid and gas exist together
e. None of the above
Q. The characteristics of a control volume are
a. The volume shape and position with respect to an observer may change
b. The volume shape and position with respect to an observer are fixed
c. There is no material flow across the boundary
d. Pulsejet
e. There is material flow across the boundary
Q. The gas turbine works on
a. Rankine cycle
b. Brayton cycle
c. Erricson cycle
d. Otto cycle
e. Carnot cycle
Q. All of the following are intensive properties EXCEPT
a. Viscosity
b. Mass
c. Pulsejet
d. Density
e. Temperature
Q. A body of weight 100 N falls freely through a distance of 10 m against an atmospheric drag force of 5 N. Considering the body as the system, the work interaction is
a. 1000 Nm
b. Pulsejet
c. 1050 Nm
d. 50 Nm
e. 950 Nm
Q. In a steam turbine when steam expands, the entropy
a. Decreases exponentially
b. Does not change
c. Increases exponentially
d. Decreases linearly
e. Increases linearly