18. Ball bearings are used in cycles, scooters etc to A.Increase the friction between the wheel and the axle B.Reduce the friction between the wheel and the axle C.Reduce the friction between ground and the whee D.None of the above
Option B Solution: The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. Reduce the friction as rolling friction is the least, rather than sliding or static friction.
