ICSE Class 6 Answered

Pulley:

1) A pulley is a simple machine wherein the wheel is not rigidly attached to the axle.

2) The wheel is free to rotate without the influence of the axle.

3) The force is applied by the rope attached to the wheel of the pulley.

 

Wheel and axle:

1) Wheel and axle is a simple machine wherein the wheel is rigidly attached to the axle.

2) The wheel cannot rotate without the axle being rotated or vice versa.

3) The force can be applied to either the wheel or the axle and can be transferred to the other.

 

A pulley is similar to a wheel and axle. But, both machines are different as wheel and axle are rigidly attached to each other but pulley is not attached to its axle.Pulley is used to change the direction of the force applied whereas wheel & axle are used to amplify rotational force.