Question

Which of the following methods results in an increase in friction?

• A. Addition of spikes to soles of shoes.
• B. Addition of wheels.
• C. Application of powder on a carrom board.
• D. Application of lubricants.

Answer 1

The correct option is A Addition of spikes to soles of shoes.

Friction can be increased by making the surface irregular. By applying lubricants and powder, the surface is made smooth and hence the friction decreases.
By adding wheels, sliding friction changes to rolling friction. As rolling friction is less than sliding friction, the friction decreases.
By adding spikes, the grip of the shoe increases and hence friction increases.