(a) A brass ball is hanging from a stiff cotton thread. Draw a neat labelled diagram showing the forces acting on the brass ball and cotton thread.

(b) Can the couple acting on a rigid body produce translatory motion?

Is it possible that an object is in the state of accelerated motion due to external force acting on it, but no work is being done by the force? Explain it with an example.

Of the three connecting wires in a household circuit:

(a) Which two of the three wires are at the same potential?

(b) In which of the three wires should the switch be connected?

A lens forms an erect, magnified and virtual image of an object. Name the lens used and draw a labelled ray diagram to show the image formation.