Bennett Mechanical Test Gears and Belt Drives 4

Question 1

Three gears mesh in a line: 20, 40, and 20 teeth. The overall ratio from first to last gear is:

Accepted Answer

1:1

Answer

The middle gear acts as an idler, so the first and last 20-tooth gears give a 1:1 ratio.

Question 2

Increasing the number of teeth on the driven gear while keeping the driver fixed will:

Accepted Answer

Lower output speed

Answer

More driven teeth means a larger ratio and slower output.

Question 3

Compared to a chain drive, a belt drive is generally:

Accepted Answer

Quieter but more prone to slipping

Answer

Belts run quietly but can slip, while chains grip teeth without slipping.

Question 4

A motor spins at 1200 RPM driving a gear ratio of 4:1 reduction. The output speed is:

Accepted Answer

300 RPM

Answer

A 4:1 reduction divides input speed by four, giving 300 RPM.

Question 5

What does a tensioner or jockey pulley do in a belt system?

Accepted Answer

Maintains proper belt tension

Answer

A tensioner keeps the belt tight to prevent slipping.

Bennett Mechanical Test Practice Test