Mechanical Aptitude Levers, Pulleys, and Gears 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 Levers, Pulleys, and Gears flashcards as text
A first-class lever has the fulcrum exactly in the middle. What is its mechanical advantage?
Answer: 1
When the fulcrum is centered, the effort arm equals the resistance arm, giving a mechanical advantage of exactly 1.
Helical gears are preferred over spur gears for high-speed applications primarily because they:
Answer: Engage more gradually, reducing noise and vibration
Helical gears have angled teeth that engage progressively, spreading the load and reducing the noise and vibration common in spur gears.
In a pulley system, if you pull 6 feet of rope to raise a load by 2 feet, what is the mechanical advantage?
Answer: 3
Mechanical advantage = distance effort moves ÷ distance load moves = 6 ÷ 2 = 3.
A pair of scissors is an example of which lever class?
Answer: First class
Scissors are first-class levers because the fulcrum (pivot pin) is between the effort (finger handles) and the load (blades cutting material).
A worm gear system provides a high gear ratio and:
Answer: Is typically non-reversible — the worm can drive the gear but not vice versa
Worm gears are self-locking in most configurations because the high friction prevents the wheel from backdriving the worm.
If a lever requires 50 lbs of effort to lift a 200 lb load, what is its mechanical advantage?
Answer: 4
Mechanical advantage = Load ÷ Effort = 200 ÷ 50 = 4.
Two meshing gears always rotate in:
Answer: Opposite directions
When two gears mesh directly, they rotate in opposite directions because their teeth push against each other.