What is the relationship between gear size and torque and speed?

What is the relationship between gear size and torque and speed?

• A. A larger gear produces more torque and slower output speed; a smaller gear increases speed
• B. A larger gear increases speed and decreases torque
• C. Gear size does not affect torque or speed
• D. Torque decreases as gear size increases, with no change in speed

Answer: (A)

Understanding gear size and how it affects speed and torque is about how gear ratios work. When two gears mesh, the size of the driven gear relative to the driving gear sets the speed and torque of the output. A larger driven gear takes more input rotations to complete one output turn, so the output slows down. At the same time, torque at the output increases because the larger gear provides more leverage, effectively multiplying the input torque (minus losses from efficiency). So, a larger gear yields more torque and a slower output speed, while a smaller gear yields less torque and a faster output speed. The idea holds in a simple two-gear setup: if the driven gear is bigger than the driver, you get a speed reduction and torque increase; if the driven gear is smaller, speed goes up and torque goes down. In practice, efficiency losses mean the numbers aren’t perfect, but the trend remains.

Understanding gear size and how it affects speed and torque is about how gear ratios work. When two gears mesh, the size of the driven gear relative to the driving gear sets the speed and torque of the output. A larger driven gear takes more input rotations to complete one output turn, so the output slows down. At the same time, torque at the output increases because the larger gear provides more leverage, effectively multiplying the input torque (minus losses from efficiency).

So, a larger gear yields more torque and a slower output speed, while a smaller gear yields less torque and a faster output speed. The idea holds in a simple two-gear setup: if the driven gear is bigger than the driver, you get a speed reduction and torque increase; if the driven gear is smaller, speed goes up and torque goes down. In practice, efficiency losses mean the numbers aren’t perfect, but the trend remains.