Gear Basics

Simple machine that transfers motion from one part of the machine to another

• Inclined Plane
• Gears
• Pulley
• All of them

BIG gears are used for

• More turning power (torque)
• More rotational speed

LITTLE gears are used for

• More turning power (torque)
• More rotational speed

Engineers often pair little gears with big gears to 

• Increase speed
• Increase torque

The larger the radius, the ______ force a turning wheel has

• MORE
• LESS

Gears spin in 

• Opposite direction
• Same direction

If you were to increase the rotational speed of a fan you would

• Use a gear train with progressively SMALLER gears (small output)

• Use a gear train with progressively BIGGER gears (large output)

How many times does the little gear has to turn in a gear train with a big gear of 72 teeth and a little gear of 12?

• 6 times 
• 4 times
• 3 times
• I don't know

What is the gear ratio of a gear train with a big gear of 48 teeth and a little gear of 12 teeth?

• 1:4
• 1:3

What does a 1:6 gear ratio mean?

• It means the small gear has to turn 6 times to turn the big gear once.
• It means the big gear has to turn 6 times to turn the small gear once.