Mechanical Aptitude Mechanical Aptitude Knowledge 2 — Questions and Answers
Question 1: A hydraulic jack uses a small piston with a 2 sq in area and a large piston with a 20 sq in area. If you apply 50 lbs on the small piston, what force does the large piston exert?
- 50 lbs
- 100 lbs
- 500 lbs (Correct answer)
- 1000 lbs
Correct answer: 500 lbs
Pascal's Law: force scales with the ratio of piston areas, so 50 × (20/2) = 500 lbs.
Question 2: Which type of gear converts rotational motion into linear motion?
- Bevel gear
- Rack and pinion (Correct answer)
- Worm gear
- Planetary gear
Correct answer: Rack and pinion
A rack and pinion converts the rotation of a pinion gear into straight-line (linear) motion of a rack.
Question 3: A wrench handle is 12 inches long and you apply 15 lbs of force. What is the torque produced?
- 0.8 ft-lbs
- 15 ft-lbs (Correct answer)
- 27 ft-lbs
- 180 ft-lbs
Correct answer: 15 ft-lbs
Torque = Force × Distance = 15 lbs × 1 ft (12 inches) = 15 ft-lbs.
Question 4: A steel beam expands when heated. This property is called:
- Elasticity
- Thermal expansion (Correct answer)
- Tensile strength
- Malleability
Correct answer: Thermal expansion
Thermal expansion is the tendency of materials to change in volume in response to temperature changes.
Question 5: Which fastener is best suited for joining two pieces where disassembly will be needed frequently?
- Rivet
- Weld bead
- Machine screw with nut (Correct answer)
- Epoxy adhesive
Correct answer: Machine screw with nut
Machine screws with nuts allow repeated assembly and disassembly without damaging the parts.
Question 6: A fixed pulley at the top of a flagpole changes the:
- Amount of force required
- Direction of the applied force (Correct answer)
- Speed of lifting
- Weight of the load
Correct answer: Direction of the applied force
A single fixed pulley only changes the direction of force — it does not provide mechanical advantage.
Question 7: Which material is the best electrical conductor?
- Rubber
- Copper (Correct answer)
- Glass
- Wood
Correct answer: Copper
Copper has very low electrical resistance and is widely used in wiring for its excellent conductivity.
Mechanical Aptitude Mechanical Aptitude Knowledge 2
A hydraulic jack uses a small piston with a 2 sq in area and a large piston with a 20 sq in area.
If you apply 50 lbs on the small piston, what force does the large piston exert?