Question

How does a refractive index of the water compare with that of a glass? Explain.

Answer 1

Hint: The ratio between the speeds of the light in the medium to speed in a vacuum is the refractive index. Speed of the light is slower in the glass as compared to water.

Formula used:
$n=\dfrac{c}{v}$

Complete step by step solution:
Let’s start with what is a refractive index: Refractive index can be simply defined as the ratio between the speeds of light in medium to speed in a vacuum.

As light travels in the medium other than the vacuum, the atoms of that medium constantly absorb and re-emit the particles of light, slowing down the speed of light. The refractive index is also known as the refraction index or index of refraction. The speed of light in a medium depends on medium properties.

In electromagnetic waves, the speed depends on the medium optical density. Optical density is the propensity to recover the absorbed electromagnetic energy of the atoms in a substance. The more material is optically thick, the slower the speed of light. The refractive is one such measure of the optical density of a medium.

Now coming to the point why glass’s refractive index is more than water, the reason is optical density of glass is more than of water. Hence the speed of the light is slower in glass and water.

The formula of the refractive index is given as.
$\Rightarrow n=\dfrac{c}{v}$
Where, n = refractive index
c = is the velocity of the light in the vacuum
v = velocity of the light in a substance.

Note:
In order to understand this solution first we saw the definition of the refraction index which is Refractive index can be simply defined as the ratio between the speeds of light in medium to speed in a vacuum and the quantities that refraction index depends which shows us the speed of light in a medium depends on medium properties. and it is the reason behind why the refractive index is different in glass and water.