The diagram below shows a lever in use:

(a) To which class of levers does it belong?

(b) Without changing the dimensions of the lever, if the load is shifted towards the fulcrum, what happens to the mechanical advantage of the lever?

A beam of metal is acted upon by two forces (parallel) of 15 N and 20 N at a distance of 35 cm from each other. At what point the beam will be balanced ?

(a) The diagram shows a bar magnet surrounded by four plotting compasses. Copy the diagram and mark the direction of the compass needle for each of the cases B, C and D.

(b) Which is the North pole, X or Y?

An object is placed in front of a converging lens. Then, draw the ray diagrams for following cases

(a) When object distance (u) > 2f.

(b) When image formed has the same size as that of object.