Mechanical Aptitude Test Mechanical Aptitude MCQ 1 — Questions and Answers
Question 1: A single fixed pulley changes the direction of a force but provides no mechanical advantage. What is the ideal mechanical advantage of a single movable pulley?
- 1
- 2 (Correct answer)
- 3
- 4
Correct answer: 2
A single movable pulley has an ideal mechanical advantage of 2 because two rope segments support the load, meaning you only need to apply half the load's weight as input force.
Question 2: A wrench applies a force of 50 N at a distance of 0.4 m from a bolt. What is the torque applied to the bolt?
- 10 N·m
- 20 N·m (Correct answer)
- 50 N·m
- 125 N·m
Correct answer: 20 N·m
Torque equals force multiplied by the perpendicular distance from the pivot point: T = F × d = 50 N × 0.4 m = 20 N·m.
Question 3: Water flows through a pipe that narrows from a diameter of 4 cm to a diameter of 2 cm. Compared to the wider section, the water speed in the narrower section is:
- Half as fast
- The same speed
- Twice as fast
- Four times as fast (Correct answer)
Correct answer: Four times as fast
By the continuity equation, flow rate (area × velocity) is constant. The diameter is halved, so the cross-sectional area is reduced by a factor of 4 (area ∝ diameter²), meaning velocity must increase by a factor of 4.
Question 4: A spring with a spring constant of 200 N/m is compressed by 0.05 m. How much elastic potential energy is stored in the spring?
- 0.10 J
- 0.25 J (Correct answer)
- 5.00 J
- 10.00 J
Correct answer: 0.25 J
Elastic potential energy is calculated using PE = ½kx², where k = 200 N/m and x = 0.05 m: PE = ½ × 200 × (0.05)² = 100 × 0.0025 = 0.25 J.
Question 5: Two pulleys are connected by a belt. The driving pulley has a radius of 10 cm and rotates at 300 RPM. If the driven pulley has a radius of 5 cm, what is its rotational speed?
- 150 RPM
- 300 RPM
- 450 RPM
- 600 RPM (Correct answer)
Correct answer: 600 RPM
For belt-connected pulleys, the speed ratio is inversely proportional to the radius ratio. The driven pulley is half the size of the driving pulley, so it spins twice as fast: 300 × (10/5) = 600 RPM.
Question 6: A screw has a pitch of 2 mm (the distance it advances per full rotation). If a force of 10 N is applied at the end of a screwdriver handle with a radius of 4 cm, what is the approximate mechanical advantage of the screw?
- 8
- 63
- 126 (Correct answer)
- 251
Correct answer: 126
The mechanical advantage of a screw equals the circumference of the handle divided by the pitch: MA = (2π × 0.04 m) / 0.002 m ≈ 0.2513 / 0.002 ≈ 126.
Mechanical Aptitude Test Mechanical Aptitude MCQ 1
A single fixed pulley changes the direction of a force but provides no mechanical advantage.
What is the ideal mechanical advantage of a single movable pulley?