Question

07. In which of the following cases more friction is desirable
(a) Movement of piston in a cylinder
(c) Running on a track
(b) Breaking of a vehicle
(d) All of the above​

Answer 1

Answer:

Friction is desirable in braking of a vehicle. As brakes are applied, friction between brake shoes and tyres opposes rotation of tyres and hence, forces it to stop.

Answer 2

(d) All of the above is the answer