Mechanical Engineering MCQs
Mechanical Engineering MCQs for competitive exams in Pakistan cover thermodynamics, fluid mechanics, machine design, manufacturing, and materials. Ideal for PPSC, FPSC, NTS, and university tests, they help students and professionals enhance concepts and problem-solving skills.
Q: Centrifugal pump impeller is a
A) Rotating blade
B) Static diffuser
C) Stationary vane
D) Fixed blade
✅ 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
✅ 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
✅ 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
✅ 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
✅ Correct Answer: D
Explanation: Carnot cycle consists of two adiabatic and two isothermal processes.