Question

What do we mean by the intensity of a light ray?
when a light ray is repeatedly reflected by a set of parallel plane mirrors the intensity of the light ray decreases after some reflections . is this because of absorption of some amount of light by mirrors ?

Answer 1

Inphysics,intensityis thepowertransferred per unitarea, where the area is measured on the plane perpendicular to the direction of propagation of the energy.^[1]In theSIsystem, it has unitswattspersquare metre(W/m²). It is used most frequently withwaves(e.g.soundorlight), in which case theaveragepower transfer over oneperiodof the wave is used.Intensitycan be applied to other circumstances where energy is transferred. For example, one could calculate the intensity of thekinetic energycarried by drops of water from agarden sprinkler. And yes u r right