Question

The coefficient of limiting friction between the surfaces of contact is the ratio of the ....................... friction to the normal reaction.

• A. Limting
• B. sliding
• C. rolling
• D. any of these

Answer 1

The correct option is A Limting

For any two surfaces in contact, the magnitude of limiting friction is directly proportional to the normal reaction between two surfaces.

The magnitude of limiting friction is directly proportional to normal reaction(R)

i.e F = $\mu$ R

therefore $\mu$ = $\frac{F}{R}$

Thus coefficient of limiting friction is the ratio between limiting friction to the normal reaction.