Is convex always coverging or it depends on the conditions like refractive indices

Asked by nagendramanikireddy999999 | 29th May, 2021, 11:50: AM

Expert Answer:

Yes. Convergence of light rays by convex lens is due to refraction of light , hence refractive index plays the crucial role.
Normally lens made of glass is surrounded by air . Refractive index of galss is 1.5 and that of air is 1 .
Hence when light travel from optcally less denser medium to optically high denser medium,
light rays are converging due to refraction. 
Suppose lens made of glass is surrounded by liquid medium that has equal or high refractive index than glass
( for example refractive index of benzene 1.5 , refractive index of carbon-di-sulphide 1.628 ) , then convergence
of light is getting affected. if surrounding medium has equal refractive index , convergence will be nil.
If surrounding medium has high refractive index divergence will take place.

Answered by Thiyagarajan K | 29th May, 2021, 02:13: PM