Question

Light enters from air into diamond which has a refractive index of 2.42. Calculate the speed of light in diamond. The speed of light in air is 3.0 x ${10}^{8}m{s}^{-1}$.

Answer 1

Step 1: Given that:

Refractive index of diamond($n$ )= $2.42$

The speed of light in air= $3\times {10}^{8}m{s}^{-1}$

Step 2: Formula used:

The refractive index of a medium is given by,

$Refractiveindexofthemedium=\frac{Speedoflightinair}{Speedoflightinmedium}$

Or,

$Speedoflightinmedium=\frac{Speedoflightinair}{Refractiveindexofthemedium}$

Step 3: Calculation of speed of light in diamond:

$Speedoflightindiamond=\frac{Speedoflightinair}{2.42}$

$Speedoflightindiamond=\frac{3\times {10}^{8}m{s}^{-1}}{2.42}$

$Speedoflightindiamond=1.24\times {10}^{8}m{s}^{-1}$

Therefore,

The speed of light in diamond will be $1.24\times {10}^{8}m{s}^{-1}$ .