Mechanical Aptitude Simple Machines and Mechanical Advantage Questions and Answers 2 — Questions and Answers
Question 1: A screw has 8 threads per inch. How far does it advance into a material with one complete revolution?
- 8 inches
- 0.125 inches (Correct answer)
- 1 inch
- 0.8 inches
Correct answer: 0.125 inches
The pitch (advance per revolution) equals 1 divided by threads per inch: 1 ÷ 8 = 0.125 inches.
Question 2: 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 a mechanical advantage of 2 because two rope segments support the load, halving the required effort.
Question 3: An inclined plane with a mechanical advantage of 5 requires 40 lbs of input force. What load can it raise?
- 8 lbs
- 45 lbs
- 200 lbs (Correct answer)
- 400 lbs
Correct answer: 200 lbs
Output force = Mechanical advantage × Input force = 5 × 40 = 200 lbs.
Question 4: Machine efficiency is calculated as:
- Output work ÷ Input work × 100% (Correct answer)
- Input work ÷ Output work × 100%
- Mechanical advantage ÷ Velocity ratio
- Force × Distance ÷ Time
Correct answer: Output work ÷ Input work × 100%
Efficiency = (Output work ÷ Input work) × 100%; a perfect machine would be 100% efficient, but friction always reduces this.
Question 5: A doorknob is an example of which simple machine?
- Lever
- Inclined plane
- Wheel and axle (Correct answer)
- Wedge
Correct answer: Wheel and axle
A doorknob is a wheel and axle — the large knob is the wheel and the spindle (latch shaft) is the axle, multiplying torque.
Question 6: A compound machine combines two or more simple machines. Its primary advantage over a single simple machine is:
- It eliminates friction entirely
- It can achieve a greater mechanical advantage (Correct answer)
- It requires no energy input
- It always changes the direction of force
Correct answer: It can achieve a greater mechanical advantage
Combining simple machines multiplies their individual mechanical advantages, allowing very large forces to be overcome with small effort.
Question 7: You push a 200 lb box up a ramp that is 8 ft long and 2 ft high. Ignoring friction, how much force is needed?
- 50 lbs (Correct answer)
- 25 lbs
- 400 lbs
- 100 lbs
Correct answer: 50 lbs
IMA = 8 ÷ 2 = 4; required force = 200 ÷ 4 = 50 lbs.
Mechanical Aptitude Simple Machines and Mechanical Advantage Questions and Answers 2
A screw has 8 threads per inch.
How far does it advance into a material with one complete revolution?