Question

scissors used to cut iron sheets has longer wedge than the scissor used o cut cloth. Why?

Answer 1

it has a greater length to reduce the effort as more the distance between the fulcrum and point of action more is the moment of force and hence the effort applied will be less.

Answer 2

actually scissors used to cut in has Short wedge.
It depends on the amount of pressure needed to cut your material. Metal is a tougher material to cut though, so the blades must be shorter to create more pressure to break through the metal. Cloth on the other hand is easier to cut through so the blades can be longer in order to cut more in each snip