Give one example of each when:

(i) Chemical energy changes into electrical energy.

(ii) Electrical energy changes into sound energy.

(i) Define moment of force.

(ii) Write the relationship between the S.I. and C.G.S. unit of moment of force.

(i) Identify the class of the lever shown in the diagram below:

(ii) How is it possible to increase the M.A. of the above lever without increasing it's length?

A satellite revolves around a planet in a circular orbit. What is the work done by the satellite at any instant? Give a reason.