Question

notches are carved on the tyres of vehicles because
1. to make the tyres look beautiful 2. to increase friction
3. to decrease friction 4. to raise the speed

Answer 1

Notches are carved on the tyres of vehicles To Increase the Friction.

Reason :

Friction is a necessary evil in our daily life.
When vehicles run on the road, there is a friction between the surface of road and tyre of the vehicle.
When road is wet, there is a layer of water which acts as lubricants and reduces friction which results in vehicle loosing the grip.
Hence to provide a better grip on slippery and wet road , the tyres are provided with treads or notches.

Answer 2

The answer is 2. to increase friction.

Notches are carved on the tyres of vehicles to increase friction. When the friction of the vehicle increases, it gives better grip and control over the vehicle. This in turn avoids skidding, especially on smooth and slippery roads.