Question

A lens behaves as a converging lens in air
and a diverging lens in water (u = 4/3).
What will be the condition on the value of
refractive index (u) of the material of the
lens?​

Answer 1

$\huge\underline{\underline{\bf \green{Question-}}}$

A lens behaves as a converging lens in air and a diverging lens in water ${\sf ( \mu_w=\dfrac{4}{3})}$ What will be the condition on the value of refractive index ${\sf \mu}$ of the material of the lens?

$\huge\underline{\underline{\bf \green{Solution-}}}$

We know that ⎯

Refractive index of air is ${\sf \mu_a=1}$

and , Refractive index of water is ${\sf \mu_w=\dfrac{4}{3}}$

And ,

lens behave as converging in air ,

i.e ${\sf \mu>1}$

and , lens behaves as diverging in water

i.e ${\sf \mu<1.33}$

⛬ We can say that

${\bf \red{Refractive\:index\:of\: material\:of\:lens\:is}}$

${\bf \red{in\:between\:1\:to\:1.33}}$