Mechanical Aptitude Mechanical Aptitude Levers, Pulleys, and Gears Questions and Answers 3 — Questions and Answers
Question 1: A wheelbarrow is an example of which class of lever?
- Second-class lever (Correct answer)
- First-class lever
- Third-class lever
- It is not a lever
Correct answer: Second-class lever
A wheelbarrow is a second-class lever where the load sits between the fulcrum (the wheel) and the effort (the handles).
Question 2: A movable pulley is attached directly to a 120-pound load. How much force is needed to lift the load using a single movable pulley?
- 60 pounds (Correct answer)
- 120 pounds
- 30 pounds
- 240 pounds
Correct answer: 60 pounds
A single movable pulley provides a mechanical advantage of 2, so the effort required is 120 divided by 2, which equals 60 pounds.
Question 3: If a driving gear with 15 teeth meshes with a driven gear with 45 teeth, what is the gear ratio?
- 3:1 (Correct answer)
- 1:3
- 15:1
- 1:15
Correct answer: 3:1
The gear ratio is driven teeth divided by driving teeth: 45 divided by 15 equals 3:1, meaning three turns of the driver produce one turn of the driven gear.
Question 4: When using a lever, moving the fulcrum closer to the load will have what effect?
- Increase mechanical advantage, requiring less effort (Correct answer)
- Decrease mechanical advantage, requiring more effort
- Have no effect on the force required
- Increase the distance the load travels
Correct answer: Increase mechanical advantage, requiring less effort
Moving the fulcrum closer to the load lengthens the effort arm relative to the load arm, increasing mechanical advantage and reducing the effort needed.
Question 5: In a block-and-tackle system with 6 rope segments supporting the load, how far must you pull the rope to raise the load 2 feet?
- 12 feet (Correct answer)
- 6 feet
- 2 feet
- 3 feet
Correct answer: 12 feet
With 6 supporting segments, you must pull 6 times the lift distance, so 6 multiplied by 2 equals 12 feet of rope.
Question 6: An idler gear is placed between two other gears in a gear train. What effect does the idler gear have on the overall gear ratio?
- It has no effect on the gear ratio (Correct answer)
- It doubles the gear ratio
- It halves the gear ratio
- It reverses the gear ratio
Correct answer: It has no effect on the gear ratio
An idler gear changes the direction of rotation but does not affect the overall gear ratio between the first and last gears.
Mechanical Aptitude Mechanical Aptitude Levers, Pulleys, and Gears Questions and Answers 3
A wheelbarrow is an example of which class of lever?