(i) State and define the S.I. unit of power.

(ii) How is the unit horse power related to the S.I. unit of power ?

(i) Why is the ratio of the velocities of light of wavelengths 4000 Å and 8000 Å in vacuum 1 : 1 ?

(ii) Which of the above wavelengths has a higher frequency?

The diagram below shows a lever in use:

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

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