Question

Why a lever of second order always increase friction​

Answer 1

A second class lever has a fulcrum on one end, the load force or resistance force in the middle and the input force or effort force on the other end. A three-hole punch has a hinge on one edge (fulcrum), you press on the other edge (input forge), and the punchers come down in the middle (output force).

A first class lever takes place when the fulcrum is between the force and load. This is possible by lifting the pole and balancing it with your hand. A second class lever takes place when the load is between the force and the fulcrum. This is possible by lifting one end of the pole while the other end is touching the ground.