Question

Which of the following statements is correct regarding friction between two surfaces in contact?

• A. Friction exists between surfaces only if they are rough.
• B. Friction can develop between smooth surfaces.
• C. Friction is solely because of the interlocking of irregularities.
• D. Friction exists between surfaces only if they are smooth.

Answer 1

The correct option is B Friction can develop between smooth surfaces.

Friction opposes relative motion between two surfaces in contact. Rough surfaces develop friction because of interlocking of irregularities. However, interlocking of irregularities is not the sole cause of friction. Smooth surfaces can also develop friction because of formation of bonds between them. This is referred to as "adhesion".