Mechanical Aptitude Knowledge Flashcards
7 cards from real MECHANICAL APTITUDE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Mechanical Aptitude Knowledge flashcards as text
A 10 kg object sits on a frictionless inclined plane at 30°. What force parallel to the slope is needed to hold it stationary? (g = 10 m/s²)
Answer: 50 N
Force along slope = mg × sin(30°) = 100 × 0.5 = 50 N.
Which valve type is best for on/off control with minimal flow restriction when fully open?
Answer: Gate valve
Gate valves have a flat gate that lifts completely out of the flow path, offering very low resistance when fully open.
The mechanical advantage of a wheel and axle is calculated as:
Answer: Wheel radius ÷ axle radius
MA = Wheel radius ÷ Axle radius; the larger the wheel compared to the axle, the greater the mechanical advantage.
What happens to electrical resistance when the length of a wire is doubled?
Answer: Resistance doubles
Resistance is directly proportional to wire length: R = ρL/A, so doubling L doubles R.
A centrifugal pump is running but not moving fluid. The most likely cause is:
Answer: Pump is cavitating due to air in the suction line
Air entrainment in the suction line prevents the pump from building pressure, causing it to lose prime and stop moving fluid.
A bolt is tightened using torque to create clamping force. Lubricating the threads before tightening will:
Answer: Increase clamping force for the same applied torque
Lubrication reduces friction losses, so more of the applied torque converts to clamping force (bolt tension).
Which simple machine is a hammer claw used to pull nails?
Answer: Lever
The hammer claw acts as a first-class lever, with the head as the fulcrum to multiply pulling force on the nail.