Question

How does it behaves when a convex lens kept in a medium whose refractive index is less than it's medium? ​

Answer 1

Answer:

Explanation:

We can find focal length of a lens by lens makers formula

i.e.  1/f = {(RI of lens/RI of medium in which kept)-1}*(1/R1-1/R2)

 Here R1 and R2 are kept acc to sign conventions.

so if the lens is kept in a medim whose refractive index is less than that of it it will have a change on its focal length but it does not changes its capability to converge the light rays. Hence it will behave as a converging lens only

The lens will have a change in its power of converging if it is kept in a medium whose refractive index is greater than that of it. if the refractive index is greater it will start behaving as a diverging lens...

Just put the values once in the formula above and you will get to know what am i trying to say