Explore topic-wise MCQs in Mechanical Engineering.

This section includes 189 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.

151.

The ratio of specific heat at constant pressure () and specific heat at constant volume () is

A. equal to one
B. less than one
C. greater than one
D. none of these
Answer» D. none of these
152.

According to Gay-Lussac law for a perfect gas, / = constant, if is kept constant.

A. True
B. False
Answer» B. False
153.

If the value of = 0 in the equation = , then the process is called

A. constant volume process
B. adiabatic process
C. constant pressure process
D. isothermal process
Answer» D. isothermal process
154.

The value of specific heat at constant pressure () is __________ that of at constant volume ().

A. less than
B. equal to
C. more than
Answer» D.
155.

The value of gas constant () in S. I. units is

A. 0.287 J/kgK
B. 2.87 J/kgK
C. 28.7 J/kgK
D. 287 J/kgK
Answer» E.
156.

The sum of internal energy () and the product of pressure and volume (.) is known as

A. workdone
B. entropy
C. enthalpy
D. none of these
Answer» D. none of these
157.

Water gas is obtained by passing air and a large amount of steam over waste coal at about 650°C.

A. Correct
B. Incorrect
Answer» C.
158.

The compression ratio is the ratio of

A. swept volume to total volume
B. total volume to swept volume
C. swept volume to clearance volume
D. total volume to clearance volume
Answer» E.
159.

When the expansion or compression takes place according to the law = , the process is known as

A. isothermal process
B. adiabatic process
C. hyperbolic process
D. polytropic process
Answer» E.
160.

The entropy is a point function and thus it is a property of the same.

A. Correct
B. Incorrect
Answer» B. Incorrect
161.

The state of a substance whose evaporation from its liquid state is complete, is known as

A. vapour
B. perfect gas
C. air
D. steam
Answer» C. air
162.

An open cycle gas turbine works on

A. Carnot cycle
B. Otto cycle
C. Joule's cycle
D. Stirling cycle
Answer» D. Stirling cycle
163.

The efficiency of Carnot cycle depends upon

A. temperature limits
B. pressure ratio
C. volume compression ratio
D. cut-off ratio and compression ratio
Answer» B. pressure ratio
164.

The gas turbine cycle with regenerator improves

A. thermal efficiency
B. work ratio
C. avoids pollution
D. none of these
Answer» B. work ratio
165.

When a gas is heated, change takes place in

A. pressure
B. volume
C. temperature
D. all of these
Answer» E.
166.

When a fluid is allowed to expand suddenly into a vaccum chamber through an orifice of large dimensions, the process is known as free expansion process.

A. True
B. False
Answer» B. False
167.

According to kinetic theory of gases, the kinetic energy of translation of a molecule is proportional to

A. 1/
B. 1/
Answer» B. 1/
168.

The amount of heat given out by the complete combustion of 1 kg of fuel is known as calorific value of solid or liquid fuel.

A. True
B. False
Answer» B. False
169.

The conditions of temperature and pressure at 0°C (273K) and 760 mm of Hg pressure are termed as __________ temperature and pressure.

A. normal
B. standard
Answer» C.
170.

The value of / for air is

A. 1
B. 1.4
C. 1.8
D. 23
Answer» C. 1.8
171.

Which of the following is an intensive property of a thermodynamic system?

A. Volume
B. Temperature
C. Mass
D. Energy
Answer» C. Mass
172.

A triatomic molecule consists of __________ atoms.

A. one
B. two
C. three
D. four
Answer» D. four
173.

A cycle consisting of __________ and two isothermal processes is known as Stirling cycle.

A. two constant pressure
B. two constant volume
C. two isentropic
D. one constant pressure, one constant volume
Answer» C. two isentropic
174.

The ratio of molar specific heats for monoatomic gas is

A. 1
B. 1.4
C. 1.67
D. 1.87
Answer» D. 1.87
175.

The general law of expansion or compression is = , The process is said to be hyperbolic, if is equal to

A. 0
B. 1
C. γ
D.
Answer» C. γ
176.

The state of a substance whose evaporation from its liquid state is partial, is known as steam.

A. Agree
B. Disagree
Answer» C.
177.

The value of universal gas constant is same for all gases.

A. Yes
B. No
Answer» B. No
178.

The numerical value of the thermal capacity and the water equivalent of the substance are the same.

A. Agree
B. Disagree
Answer» B. Disagree
179.

The area under the temperature-entropy curve (i. e. - curve) of any thermodynamic process represents the workdone during the process.

A. Agree
B. Disagree
Answer» C.
180.

The heating of a gas at constant pressure is governed by Charles' law.

A. True
B. False
Answer» B. False
181.

When a gas is heated at constant volume

A. its temperature will increase
B. its pressure will increase
C. both temperature and pressure will increase
D. neither temperature nor pressure will increase
Answer» D. neither temperature nor pressure will increase
182.

The hard coke is obtained when carbonisation of coal is carried out at

A. 300° to 500°C
B. 500° to700°C
C. 700° to 900°C
D. 900° to 1100°C
Answer» E.
183.

According to First law of thermodynamics,

A. total internal energy of a system during a process remains constant
B. total energy of a system remains constant
C. workdone by a system is equal to the heat transferred by the system
D. internal energy, enthalpy and entropy during a process remains constant
Answer» C. workdone by a system is equal to the heat transferred by the system
184.

Stirling cycle consists of

A. two constant volume and two isentropic processes
B. two constant volume and two isothermal processes
C. two constant pressure and two isothermal processes
D. one constant volume, one constant pressure and two isentropic processes
Answer» C. two constant pressure and two isothermal processes
185.

For the same compression ratio, the efficiency of Diesel cycle is __________ Otto cycle.

A. greater than
B. less than
C. equal to
Answer» C. equal to
186.

In open cycle gas turbine plants

A. the indirect heat exchanger and cooler is avoided
B. direct combustion system is used
C. a condenser is used
D. all of the above
Answer» E.
187.

The efficiency of Ericsson cycle is __________ Carnot cycle.

A. greater than
B. less than
C. equal to
Answer» D.
188.

One molecule of oxygen consists of __________ atoms of oxygen.

A. 2
B. 4
C. 8
D. 16
Answer» B. 4
189.

In an isolated system, neither the heat and work nor the, mass of the working substance crosses the boundary of the system.

A. True
B. False
Answer» B. False