Answer:
Wheel and axle consists of two coaxial cylinders of different diameters. Various examples of wheel and axle are used in our daily life. Some examples of such wheel and axles are string-roller, screwdriver, MADANI, ROTE PING, spanners, knobs of a door, steering of vehicles etc. Most of them are used for magnifying effort but some are also used to gain speed like MADANI and ROTE PING. In wheel and axles, usually effort is applied on big cylinder called wheel and is overcome bya small cylinder called axle.