What is the use of a lever if its mechanical advantage is

(a) more than 1,

(b) equal to 1, and

(c) less than 1?

(a) When the mechanical advantage is more the 1, the lever serves as force multiplier i.e. it enables us to overcome a large resistive force (load) by a small effort.

(b) When the mechanical advantage is equal to 1, the lever has effort arm and load arm of equal lengths like in a physical balance with both arms equal in length.

(c) When the mechanical advantage is less than 1, the levers are used to obtain the gain in speed. This means that the displacement of load is more as compared to the displacement of effort.