Why is door handle at the free end of doors?

Door handles are placed at the edge of the doors so as to increase the moment of force or torque by which we,humans have to put the least effort in opening or closing it.
 Moment of force or torque= perpendicular distance from the axis of rotation x force applied

hence, more the distance from the axis of rotation, more is the torque or turning effect produced.

You can try it by yourself...where do you need to apply more force? on the edges or on the hinge side to open a door??..experiment it ...

mark brainliest if it helps! :) good luck