Lever is a rigid bar (straight, curved or bent) and is hinged at one point. It is free to rotate about the hinged end called the fulcrum.
Example: Crow bar, pair of scissors, fire tongs, etc.
It may be noted that there is a point for an effort called the effort arm. Another point for overcoming resistance or lifting load is called load arm.
Types of Lever:
Though the levers are of two types, the following are important from the subject’s point of view.
A lever which consists of one bar having one fulcrum is known as a simple lever.
A lever which consists of a number of simple levers is known as a compound lever.