When the light enters from air to glass, the angle of incidence and refraction in air and glass are $45^o$and $30^o$. The refractive index of the glass is:

The refractive index of glass is a measure of how much the speed of light slows down when it passes from air into glass. In this case, the refractive index of the glass is given as 2, which indicates that light travels twice as slowly in glass compared to air.

The refractive index of the glass is $\sqrt{2}$.
Given,
Angle of the incident, $\mathit{i }= 45^o$

Angle of the refraction, $\mathit{r }= 30^o$

Using Snell's law
   ${\mathrm{n}}_{\mathrm{glass}}=\frac{\mathrm{Sin}\mathrm{i}}{\mathrm{Sin}\mathrm{r}}$
$\Rightarrow {\mathrm{n}}_{\mathrm{glass}}=\frac{\mathrm{Sin} {45}^{\mathrm{o}}}{\mathrm{Sin} {30}^{\mathrm{o}}}$
$\Rightarrow {\mathrm{n}}_{\mathrm{glass}}=\frac{1/\sqrt{2}}{1/2}$This result confirms that the refractive index of the glass is 2. It demonstrates that light bends when entering glass due to its denser medium, slowing down and changing its direction based on Snell’s Law. This principle is fundamental in understanding optics and designing lenses.
$\Rightarrow {\mathrm{n}}_{\mathrm{glass}}=\sqrt{2}$