Question

speed of light in glass is 2×10^8m/s. find the refractive index of the glass​

Answer 1

Given :-

Speed of light in glass = 2 × 10^8

To Find :-

Refractive index

Solution :-

We know the speed of light in air is 3 × 10^8

Therefore,

Refractive index = Speed of light in glass / speed of light in air

Refractive index = 2 × 10^8/ 3 × 10^8

= 1.5

Answer 2

$\textbf{\huge\underline{\underline\red{solution} : - }} \\ \\ \textit{ \tt{The refractive index of a medium }} \\ \textit{ \tt{can be calculated using the }}\\ \textit{ \tt{following formula:}}\\ \textit{ \tt{</p><p></p><p> \red{ => n }}} \tt \red{= \frac{c}{v} }\\ \textit{ \tt{where}}\\ \textit{ \tt{ \red{n }is the refractive index of }}\\ \textit{ \tt{the medium}}.\\ \textit{ \tt{ \red{c }is the velocity of light }}\\ \textit{ \tt{in vacuum.}} \tt \purple{( 3 × {10}^{8} m/s)}\\ \textit{ \tt{</p><p></p><p> \red{v} is the velocity of light }}\\ \textit{ \tt{in the medium.}} \\ \\ \tt \underline\red{given } : - </p><p> \\ \\ \tt \red{c } \: of \: air = 3 × {10}^{8} m/s \\ \tt \red{v} \: of \: glass = 2× {10}^{8} m/s \\ \tt \red{n} \: is \: refractive \: index = \: ? \\ \\ \tt \purple {by \: formula} \\ \tt \red{ = > n = \frac{c}{v } } \\ \\ \tt \purple{= > n = \frac{ 3 × {10}^{8} }{ 2 × {10}^{8} } }$

=> n = 1.5

hence refractive index n = 1.5