Solved 2024 Question Paper ICSE Class 10 Physics — Question 4

(a) Given,

Refractive index of glass with respect to water = $\dfrac{9}{8}$

Then, according to the principle of reversibility of light

Refractive index of water with respect to glass =
$\dfrac{1}{\text {Refractive index of glass w.r.t water}} = \dfrac{1}{\dfrac{9}{8}}=\dfrac{8}{9}$

(b) Principle of reversibility of light

(c) If temperature is changed of water then the ratio $\dfrac{9}{8}$ will also change as refractive index of medium is inversely proportional to the temperature i.e., on increasing temperature refractive index of a medium decreases and vice versa.

So, If we change the temperature of water,then the ratio $\dfrac{9}{8}$ will not remain the same.