Mechanical Engineering MCQs
Mechanical Engineering MCQs are a crucial resource for students and job seekers preparing for competitive tests in Pakistan. This section features MCQs from all major areas including thermodynamics, fluid mechanics, machine design, manufacturing processes, engineering materials, and mechanics of solids. These questions are crafted to meet the standards of exams like PPSC, FPSC, NTS, and university entry or semester tests. Each MCQ is aimed at testing your fundamental understanding and problem-solving ability, making them perfect for both fresh graduates and experienced professionals. With a wide range of topics, this category ensures a comprehensive practice session for anyone looking to ace Mechanical Engineering exams.
Q: When metal is plastically deformed
A) It returns to original shape
B) Strain becomes zero
C) It undergoes permanent deformation
D) It fails
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Correct Answer: C
Explanation: Plastic deformation causes permanent change in shape.
Q: Draft in a boiler system is required for
A) Fuel combustion
B) Pump operation
C) Steam formation
D) Water level maintenance
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Correct Answer: A
Explanation: Draft supplies air for combustion and removes flue gases.
Q: Tensile strength is maximum in
A) Copper
B) Wrought iron
C) Cast iron
D) Mild steel
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Correct Answer: D
Explanation: Mild steel has good ductility and high tensile strength.
Q: Steam is a
A) Superheated liquid
B) Vapor
C) Perfect gas
D) Incompressible fluid
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Correct Answer: B
Explanation: Steam is water in vapor state.
Q: Cutting fluids are used in machining to
A) Harden tool
B) Increase friction
C) Cool tool and workpiece
D) Remove chips
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Correct Answer: C
Explanation: Cooling and lubrication are the primary functions.
Q: Centrifugal pump impeller is a
A) Rotating blade
B) Static diffuser
C) Stationary vane
D) Fixed blade
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Correct Answer: A
Explanation: Impeller rotates to impart kinetic energy to fluid.
Q: Stress concentration occurs due to
A) Large radius
B) Sudden changes in section
C) Uniform loading
D) Long shafts
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Correct Answer: B
Explanation: Sharp corners or holes increase local stress.
Q: S-N curve is used to determine
A) Hardness
B) Creep
C) Yield strength
D) Fatigue strength
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Correct Answer: D
Explanation: S-N curve relates number of cycles to failure under fatigue loading.
Q: Lathe operation of reducing diameter is called
A) Facing
B) Reaming
C) Turning
D) Drilling
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Correct Answer: C
Explanation: Turning reduces the outer diameter of a workpiece.
Q: Carnot cycle is composed of
A) Only reversible processes
B) Two isobaric and two isothermal processes
C) Four adiabatic processes
D) Two adiabatic and two isothermal processes
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Correct Answer: D
Explanation: Carnot cycle consists of two adiabatic and two isothermal processes.