Mechanical advantage has no unit, why?
Mechanical advantage (MA) is theratio of Load to Effort. Both load and effort are forces, i.e., MA is the ratio of two same physical quantities. So, it has no unit.
Though there is no gain in mechanical advantage by using a single fixed pulley it is used in practice, why?
Though there is no gain in mechanical advantage by using a single fixed pulley it is used in practice, it is because of the following reasons: