CPS Mechanical Aptitude Principles 2 — Questions and Answers
Question 1: Two gears mesh together. The driver gear has 10 teeth and the driven gear has 30 teeth. If the driver turns at 60 RPM, how fast does the driven gear turn?
- 20 RPM (Correct answer)
- 60 RPM
- 90 RPM
- 180 RPM
Correct answer: 20 RPM
A larger driven gear (30 teeth vs 10) turns three times slower: 60 ÷ 3 = 20 RPM.
Question 2: When two meshed gears are in direct contact, how do their rotation directions compare?
- They rotate in opposite directions (Correct answer)
- They rotate in the same direction
- Direction depends on gear size
- One stays still
Correct answer: They rotate in opposite directions
Two externally meshed gears always turn in opposite directions.
Question 3: A first-class lever has the fulcrum located where?
- Between the effort and the load (Correct answer)
- At the same point as the load
- At the effort end only
- Outside both the effort and load
Correct answer: Between the effort and the load
In a first-class lever, such as a seesaw or crowbar, the fulcrum sits between the effort and the load.
Question 4: To lift a heavy load with the least effort using a lever, where should you apply the force?
- As far from the fulcrum as possible (Correct answer)
- As close to the fulcrum as possible
- Directly on the fulcrum
- On top of the load
Correct answer: As far from the fulcrum as possible
A longer effort arm increases mechanical advantage, reducing the force needed.
Question 5: A fixed single pulley changes which property of an applied force?
- The direction of the force (Correct answer)
- The magnitude of the force
- Both direction and magnitude
- Neither direction nor magnitude
Correct answer: The direction of the force
A fixed pulley redirects force but provides no mechanical advantage, so the force magnitude stays the same.
Question 6: Water flows through a pipe that narrows from a wide section to a narrow section. What happens to the water's speed in the narrow section?
- It increases (Correct answer)
- It decreases
- It stays the same
- It stops
Correct answer: It increases
By continuity, fluid speeds up when forced through a smaller cross-sectional area.
Question 7: Which simple machine is a doorknob an example of?
- Wheel and axle (Correct answer)
- Inclined plane
- Pulley
- Wedge
Correct answer: Wheel and axle
A doorknob turns a small axle using a larger knob, making it a wheel-and-axle.
CPS Mechanical Aptitude Principles 2
Two gears mesh together.
The driver gear has 10 teeth and the driven gear has 30 teeth.
If the driver turns at 60 RPM, how fast does the driven gear turn?