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: Cast iron is widely used because of its
A) High strength
B) Good machinability
C) Ductility
D) High toughness
β
Correct Answer: B
Explanation: Cast iron is easy to cast and machine.
Q: The angle between two surfaces of a cutting tool is called
A) Clearance angle
B) Rake angle
C) Helix angle
D) Relief angle
β
Correct Answer: B
Explanation: Rake angle affects the cutting efficiency and chip flow.
Q: Velocity ratio in a screw jack is
A) Always less than 1
B) Always more than 1
C) Equal to 1
D) Zero
β
Correct Answer: B
Explanation: Due to the mechanical advantage of threads, the velocity ratio is greater than 1.
Q: Newtonβs second law is concerned with
A) Force and acceleration
B) Velocity and mass
C) Acceleration and inertia
D) Friction and reaction
β
Correct Answer: A
Explanation: Newton's second law: Force = Mass Γ Acceleration.
Q: First law of thermodynamics is the law of
A) Energy conservation
B) Ideal gases
C) Friction
D) Entropy
β
Correct Answer: A
Explanation: It states energy can neither be created nor destroyed.
Q: When a beam is subjected to pure bending
A) Deflection is zero
B) No stress develops
C) Only normal stress exists
D) Shear stress occurs
β
Correct Answer: C
Explanation: Pure bending causes only normal stresses in cross section.
Q: Factor of safety is defined as
A) Breaking load / Design load
B) Yield stress / Allowable stress
C) Maximum load / Working load
D) Ultimate stress / Allowable stress
β
Correct Answer: D
Explanation: It provides a margin between expected and failure loads.
Q: Gear ratio is determined by
A) Gear size
B) Torque
C) Pitch circle diameter
D) Number of teeth
β
Correct Answer: D
Explanation: Gear ratio is calculated by dividing teeth of driven gear by driving gear.
Q: Specific speed of a pump is used to classify
A) Cavitation
B) Impellers
C) Turbines
D) Flow types
β
Correct Answer: B
Explanation: Specific speed helps select the most efficient pump design.
Q: Diesel engines use
A) Battery ignition
B) Carburetor
C) Spark plug
D) Fuel injection
β
Correct Answer: D
Explanation: Diesel engines use compression ignition with direct fuel injection.