M C Q s D r i v e

Mechanical Engineering Mcqs 1919 MCQs [All-Courses]

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Mechanical Engineering MCQs prepared for job test and interview preparation, especially for fresh graduates, students, and candidates appearing in competitive exams. These multiple-choice questions cover key topics such as Machine Design, Theory of Machines, Hydraulic Machines, and other important mechanical engineering concepts.

Change in internal energy in a closed system is equal to heat transferred if the reversible process takes place at constant_______________?

A pressure
B temperature
C volume
D internal energy
Correct Answer: volume

Isochoric process is one in which___________________?

A free expansion takes place
B very little mechanical work is done by the system
C no mechanical work is done by the system
D all parameters remain constant
Correct Answer: no mechanical work is done by the system

Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant________________?

A pressure
B temperature
C volume
D internal energy
Correct Answer: pressure

Energy can neither be created nor destroyed but can be converted from one form to other is inferred from_________________?

A zeroth low of thermodynamic
B first law of thermodynamics
C second law to thermodynamics
D basic law of thermodynamics
Correct Answer: first law of thermodynamics

Entropy change depends on___________________?

A heat transfer
B mass transfer
C change of temperature
D thermodynamic state
Correct Answer: heat transfer

A gas is compressed in a cylinder by a movable piston to a volume one-half its original volume. During the process 300 kJ heat left the gas and internal energy remained same. The work done on gas in Nm will be___________________?

A 300 Nm
B 300,000 Nm
C 30 Nm
D 3000 Nm
Correct Answer: 300,000 Nm

Minimum work in compressor is possible when the value of adiabatic index n is equal to_________________?

A 0.75
B 1
C 1.27
D 1.35
Correct Answer: 1

In order that a cycle be reversible, following must be satisfied ________________?

A free expansion or friction resisted expansion/compression process should not be encountered
B when heat is being absorbed, temperature of hot source and working sub¬stance should be same
C when beat is being rejected, temperature of cold source and working sub-stance should be same
D all of the above
Correct Answer: all of the above

The specific heat of air increases with increase in __________________?

A temperature
B pressure
C both pressure and temperature
D variation of its constituents
Correct Answer: temperature

In a free expansion process___________________?

A work done is zero
B heat transfer is zero
C both A. and B. above
D work done is zero but heat increases
Correct Answer: both A. and B. above