Torque:

To make sure that the torque is equal on both sides, the following has to apply:

Thus little force and a long lever arm can have the same effect as great force and a short lever arm.

Attention:
Lever arm (green line) and line of application of the force (red, dashed line) must be at right angle.

And something else for reflecting:

Have you ever tried to close a door by pushing close to the axis of rotation (that is close to the hinge)? Why is it much easier, if you increase the distance to the axis of rotation and push the door with the handle?