What is reflector?

What is electrophoresis ? What is its significance ?

What is electric energy ? what is its SI unit?

What is electric energy? what is its SI unit?

What is haemozoin and what is its effect?

What is torsion? What is its effect?

What are solar reflectors and solar concentrators?

If a parabolic reflector is 20 cm in diameter and 5 cm deep, find the focus.

Light with enrgy flux of 9 xx 10^5 W m^(-2) falls of a non - refleting surface at normal incidence.If trhe surface has an area of 50 cm^2 ,find average force exerted on the surface during an intervl of 10 minutes.How will the result get modified ,if the surface is a perfect reflector?