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: How does increasing piston speed affect volumetric efficiency in an engine?
A) No effect
B) Decreases it
C) Doubles it
D) Increases it
✅ Correct Answer: B
Explanation: Higher piston speed reduces the time for air intake, lowering volumetric efficiency.
Q: Bernoulli’s equation is applicable only to which type of fluid?
A) Incompressible and non-viscous
B) Non-Newtonian fluid
C) Real gas
D) Compressible and viscous
✅ Correct Answer: A
Explanation: Bernoulli’s equation assumes ideal fluid conditions: incompressible, steady, and non-viscous.
Q: The modulus of resilience is the area under which part of the stress-strain curve?
A) Elastic region
B) Necking region
C) Plastic region
D) Fracture point
✅ Correct Answer: A
Explanation: It measures energy absorbed per unit volume before yielding begins.
Q: How does thermal expansion affect the fit between shaft and hole in engineering assemblies?
A) Tightens fit
B) No effect
C) Loosens fit
D) Causes leakage
✅ Correct Answer: A
Explanation: Heating causes expansion, which tightens interference fits.
Q: Euler’s formula is used for calculating buckling load of which structures?
A) Shafts
B) Plates
C) Beams
D) Columns
✅ Correct Answer: D
Explanation: Euler’s formula predicts the critical buckling load for long slender columns under axial compression.