Explore topic-wise MCQs in Mechanical Engineering Questions.

This section includes 446 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.

1.

Which of the following variables controls the physical properties of a perfect gas_________________?

A. pressure
B. temperature
C. volume
D. all of the above
E. atomic mass
Answer» E. atomic mass
Discussion
2.

Which point is taken as the standard reference point to define the Kelvin temperature scale?

A. Boiling point of water
B. Triple point of water
C. Freezing point of water
D. Boiling point of Mercury
Answer» C. Freezing point of water
Discussion
3.

Which processes do occur in the Brayton cycle?

A. two reversible adiabatic processes and two reversible isochoric processes
B. two reversible adiabatic processes and two reversible isobaric processes
C. two reversible adiabatic processes and two reversible isothermal processes
D. two reversible adiabatic processes and two reversible isentropic processes
Answer» C. two reversible adiabatic processes and two reversible isothermal processes
Discussion
4.

Which processes do the Rankine cycle contain?

A. two isothermal and two isochoric processes
B. two isentropic and two isobaric processes
C. two isentropic and two isothermal processes
D. two isothermal and two isobaric processes
Answer» C. two isentropic and two isothermal processes
Discussion
5.

Which property of a system is constant in reversible adiabatic process?

A. pressure
B. volume
C. temperature
D. entropy
Answer» E.
Discussion
6.

Which refrigerant is widely used in refrigeration facilities of food as cooling of fresh vegetables, dairy products, meat and fish and similar process industries?

A. sulphur dioxide
B. ethyl chloride
C. propane
D. ammonia
Answer» E.
Discussion
7.

Which temperature can be measured by an instrument called psychrometer?

A. dry bulb temperature
B. wet bulb temperature
C. both a. and b.
D. none of the above
Answer» D. none of the above
Discussion
8.

Which thermodynamic process cannot be plotted accurately on thermodynamic coordinates?

A. reversible process
B. irreversible process
C. both reversible and irreversible processes
D. none of the above
Answer» C. both reversible and irreversible processes
Discussion
9.

Which thermodynamic cycle, for the same condition, has highest efficiency among the others?

A. Carnot cycle
B. Stirling cycle
C. Ericsson cycle
D. None. All of the above have same efficiency
Answer» E.
Discussion
10.

Which type of energy is required to expend in vapour absorption refrigeration system?

A. high-grade energy
B. low-grade energy
C. medium-grade energy
D. none of the above
Answer» C. medium-grade energy
Discussion
11.

Which type of function the entropy is?

A. a path function
B. a point function
C. both a. and b.
D. none of the above
Answer» C. both a. and b.
Discussion
12.

Which will be a suitable condition of exergy loss and entropy generation for thermodynamically efficient process?

A. maximum exergy loss with minimum rate of entropy generation
B. minimum exergy loss with maximum rate of entropy generation
C. maximum exergy loss with maximum rate of entropy generation
D. minimum exergy loss with minimum rate of entropy generation
Answer» E.
Discussion
13.

Why do the airplanes fly at higher altitude during the long flights?

A. to avoid collisions as they are at very high speed and controlling will be difficult if something (like towers, hills) comes in the way
B. it is easy to communicate with satellites at high altitudes
C. to save the fuel as air at higher altitude exerts smaller drag force on aircraft
D. none of the above
Answer» D. none of the above
Discussion
14.

Work done in a constant volume process is

A. negative
B. zero
C. positive
D. none of the above
Answer» C. positive
Discussion
15.

Work done in a free expansion process is___________________?

A. + ve
B. -ve
C. zero
D. maximum
E. minimum
Answer» D. maximum
Discussion
16.

Work done in an adiabatic process between a given pair of end states depends on__________________?

A. the end states only
B. particular adiabatic process
C. the value of index n
D. the value of heattransferred
E. mass of the system
Answer» B. particular adiabatic process
Discussion
17.

Work done is zero for the following process_________________?

A. constant volume
B. free expansion
C. throttling
D. all Of the above
E. none of the above
Answer» E. none of the above
Discussion
18.

Work involved in a thermodynamic process is

A. a path function
B. a point function
C. a transfer function
D. none of the above
Answer» B. a point function
Discussion
19.

Zeroth law of thermodynamics________________?

A. deals with conversion of mass and energy
B. deals with reversibility and irreversibility of process
C. states that if two systems are both in equilibrium with a third system, they are in thermal equilibrium with each other
D. deals with heat engines
E. does not exist
Answer» D. deals with heat engines
Discussion
20.

Which of the following quantities is not the property of the system__________________?

A. pressure
B. temperature
C. specific volume
D. heat
E. density
Answer» E. density
Discussion
21.

Which of the following processes is irreversible process___________________?

A. isothermal
B. adiabatic
C. throttling
D. all of the above
E. none of the above
Answer» D. all of the above
Discussion
22.

Which of the following processes are thermodynamically reversible___________________?

A. throttling
B. free expansion
C. constant volume and constant pressure
D. hyperbolic and pV = C
E. isothermal and adiabatic
Answer» F.
Discussion
23.

Which of the following parameters is constant for a mole for most of the gases at a given temperature and pressure___________________?

A. enthalpy
B. volume
C. mass
D. entropy
E. specific volume
Answer» C. mass
Discussion
24.

Which of the following laws is applicable for the behavior of a perfect gas__________________?

A. Boyle’s law
B. Charles’law
C. Gay-Lussac law
D. all of the above
E. Joule’s law
Answer» E. Joule’s law
Discussion
25.

Which of the following items is not a path function ____________________?

A. heat
B. work
C. kinetic energy
D. vdp
E. thermal conductivity
Answer» F.
Discussion
26.

Which of the following is/are mode/s of storage of internal energy in a system?

A. Macroscopic energy mode
B. Microscopic energy mode
C. both a. and b.
D. none of the above
Answer» D. none of the above
Discussion
27.

Which of the following is the property of a system___________________?

A. pressure and temperature
B. internal energy
C. volume and density
D. enthalpy and entropy
E. all of the above
Answer» F.
Discussion
28.

Which of the following is not the intensive property___________________?

A. pressure
B. temperature
C. density
D. heat
E. specific volume
Answer» E. specific volume
Discussion
29.

Which of the following is NOT the heat engine cycle

A. refrigerator
B. stem power plant
C. mass of gas confined in a cylinder and piston machine
D. none of the above
Answer» B. stem power plant
Discussion
30.

Which of the following is NOT a type of heat pump?

A. vapour compression type
B. vapour absorption type
C. both a. and b.
D. none of the above
Answer» E.
Discussion
31.

Which of the following is chosen as a standard thermometric substance?

A. Gas
B. Thermocouple
C. Electric resistance
D. Mercury
Answer» B. Thermocouple
Discussion
32.

Which of the following is an irreversible cycle_____________________?

A. carnot
B. Stirling
C. ericsson
D. all of the above
E. none of the above
Answer» F.
Discussion
33.

Which of the following is a reversed heat engine?

A. Heat pump
B. Refrigerator
C. both a. and b.
D. none of the above
Answer» D. none of the above
Discussion
34.

Which of the following cycles is not a reversible cycle_____________________?

A. Carnot
B. Ericsson
C. Stirling
D. Joule
E. none of the above
Answer» F.
Discussion
35.

Which of the following cycles has maximum efficiency_____________?

A. Rankine
B. Stirling
C. Carnot
D. Brayton
E. Joule
Answer» D. Brayton
Discussion
36.

Which of the following can be regarded as gas so that gas laws could be applicable, within the commonly encountered temperature limits ?

A. 02, N2, steam, C02
B. Oz, N2, water vapour
C. S02, NH3, C02, moisture
D. 02, N2, H2, air
E. steam vapours, H2, C02
Answer» E. steam vapours, H2, C02
Discussion
37.

Which loss does present in actual vapour power cycle at the exit of the boiler and at the entry of the turbine?

A. friction loss
B. constant pressure heat loss
C. both a. and b.
D. none of the above
Answer» D. none of the above
Discussion
38.

Which law states that the specific heat of a gas remains constant at all temperatures and pressures______________________?

A. Charles’ Law
B. Joule’s Law
C. Regnault’s Law
D. Boyle’s Law
E. there is no such law
Answer» D. Boyle’s Law
Discussion
39.

Which law of thermodynamics expresses that the energy is always conserved quantity wise?

A. First law
B. Second law
C. Third law
D. none of the above
Answer» B. Second law
Discussion
40.

Which law states that the internal energy of a gas is a function of temperature__________________?

A. Charles’ law
B. Joule’s law
C. Regnault’s law
D. Boyle’s law
E. there is no such law
Answer» C. Regnault’s law
Discussion
41.

Which law of thermodynamics is the basis of temperature measurement?

A. Zeroth law of thermodynamics
B. First law of thermodynamics
C. Second law of thermodynamics
D. none of the above
Answer» B. First law of thermodynamics
Discussion
42.

Which is the affecting factor for the fact that turbine work output is more than pump work input in vapour power cycle for the same pressure ratio?

A. specific heat added to the working fluid
B. specific volume of working fluid
C. both a. and b.
D. none of the above
Answer» C. both a. and b.
Discussion
43.

Which is a state of a substance from which a phase change occurs without a change of pressure or temperature?

A. pure state
B. phase state
C. saturation state
D. critical state
Answer» D. critical state
Discussion
44.

Which in the examples is NOT a pure substance?

A. baking soda
B. diamond
C. sea water
D. table salt
Answer» D. table salt
Discussion
45.

Which expansion device is capable of regulating the flow of refrigerant according to the load on the evaporator?

A. capillary tube
B. throttle valve
C. both a. and b.
D. none of the above
Answer» C. both a. and b.
Discussion
46.

Which device is used for the expansion of refrigerant in vapour compression refrigeration cycle?

A. throttling valve
B. capillary tube
C. either throttling valve or capillary tube
D. none of the above
Answer» D. none of the above
Discussion
47.

Which cycle is more suitable for the reciprocating engines?

A. Brayton cycle
B. Rankine cycle
C. Otto cycle
D. All of the above are similarly efficient for same capacity
Answer» D. All of the above are similarly efficient for same capacity
Discussion
48.

Which cycle is more efficient for electricity generation plant?

A. Brayton cycle
B. Rankine cycle
C. Otto cycle
D. none of the above
Answer» C. Otto cycle
Discussion
49.

Which condition is correct according to the entropy principle?

A. the entropy of an isolated system can never decreases
B. the entropy of a system remains constant only when the process is reversible
C. the entropy of a system increases when the process is irreversible
D. all of the above
Answer» E.
Discussion
50.

Which concept provides the useful measure of quality of energy?

A. entropy
B. exergy
C. energy
D. none of the above
Answer» C. energy
Discussion