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: When metal is plastically deformed
A) It returns to original shape
B) Strain becomes zero
C) It undergoes permanent deformation
D) It fails
✅ 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
✅ 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
✅ 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
✅ 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
✅ Correct Answer: C
Explanation: Cooling and lubrication are the primary functions.