Which statement best describes the effect of increasing the size of the input gear relative to the output gear in a gear train?

• A. Increase speed
• B. Increase torque and reduce speed
• C. No effect on torque or speed
• D. Only affects rotation direction

Answer: (B)

When the input gear is larger than the output gear, the gear ratio becomes greater than one. A larger driver turns the smaller driven gear fewer times per minute, so the output speed drops. Because power must stay roughly the same (ignoring losses), the decrease in speed is balanced by an increase in torque at the output. So you get more torque at a slower speed. Rotation direction isn’t determined by gear size alone and depends on the overall gear arrangement, so the primary effect here is the boost in torque and the reduction in speed.