Types of lever and their uses :-
The levers may be first type, second type and third type. In the first type of levers , the fulcrum is in between the load and effort. Since the effort arm is greater than load arm, therefore, the mechanical advantage is more than one . Such type of levers are commonly found in bell cranked levers used in railway signalling arrangement, rocker arm in internal combustion engines, handle of a hand pump,hand wheel of a punching press, beam of a balance, foot lever etc. In the second type of levers, the load is in between the fulcrum and effort. In this case, the effort the arm is more than load arm, therefore, the mechanical advantage is more than one.The application of such type of levers is found in levers of loaded safety valves. In the third type of levers, the effort is in between the fulcrum and load. Since the effort arm, in this case, is less than the load arm, therefore, the mechanical advantage is less than one. A pair of tongs, the tradl...