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?

(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?

State the energy changes in the following cases while in use:

(i) An electric iron.

(ii) A ceiling fan.