The product of the diametral pitch and circular pitch is equal to ______.

The module is the reciprocal of ______.

Mitre gears are used for _______.

The contact ratio for gears is always ______.

Interference can be avoided in involute gears with 20° pressure angle by ______.

For a speed ratio of 100, the smallest gearbox is obtained by using a ______.

The radial distance of a tooth from the pitch circle to the top of the tooth is called ______.

The working depth of a gear is the radial distance from the ____.

When two spur gears having involute profiles on their teeth engage, the line of action is tangential to the ______ circles.

Tooth thickness on the pitch line of involute gear in terms of the module (m) is equal to _____.