Bennett Mechanical Test Gears and Belt Drives 2 — Questions and Answers
Question 1: A driver gear with 10 teeth meshes with a driven gear of 40 teeth. What is the gear ratio?
- 1:4 (Correct answer)
- 4:1
- 1:2
- 2:1
Correct answer: 1:4
The ratio of driver to driven teeth is 10:40, which simplifies to 1:4.
Question 2: When a small gear drives a large gear, what happens to the rotational speed?
- Speed decreases (Correct answer)
- Speed increases
- Speed stays the same
- Gear stops turning
Correct answer: Speed decreases
Driving a larger gear reduces output speed while increasing torque.
Question 3: Two gears that mesh directly will rotate in which directions relative to each other?
- Opposite directions (Correct answer)
- The same direction
- They cannot rotate
- Both stop
Correct answer: Opposite directions
Externally meshed gears always turn in opposite directions.
Question 4: An idler gear placed between a driver and driven gear primarily changes what?
- The direction of rotation (Correct answer)
- The overall gear ratio
- The number of teeth needed
- The torque output only
Correct answer: The direction of rotation
An idler reverses rotation direction without altering the overall ratio.
Question 5: If a belt drive has a large pulley driving a small pulley, the small pulley will turn:
- Faster (Correct answer)
- Slower
- At the same speed
- In reverse only
Correct answer: Faster
A smaller driven pulley spins faster than the larger driving pulley.
Question 6: A crossed (figure-eight) belt between two pulleys causes them to rotate:
- In opposite directions (Correct answer)
- In the same direction
- At twice the speed
- Without slipping ever
Correct answer: In opposite directions
Crossing the belt reverses the rotation of the driven pulley.
Question 7: What is the main advantage of a gear train that reduces speed?
- It increases torque (Correct answer)
- It reduces torque
- It eliminates friction
- It removes the need for a motor
Correct answer: It increases torque
Speed reduction trades rotational speed for greater torque output.
Bennett Mechanical Test Gears and Belt Drives 2
A driver gear with 10 teeth meshes with a driven gear of 40 teeth.
What is the gear ratio?