Define mechanical advantage in a lever.

(N/A) The mechanical advantage $(MA)$ of a lever is defined as the ratio of the load force $(L)$ to the effort force $(E)$.
Mathematically,it is expressed as:
$MA = \frac{L}{E}$
Alternatively,in terms of distances from the fulcrum,it is the ratio of the effort arm length $(d_E)$ to the load arm length $(d_L)$:
$MA = \frac{d_E}{d_L}$
$A$ mechanical advantage greater than $1$ indicates that the lever multiplies the input force,making it easier to lift heavy loads.