Question

If a ray of light enters from alcohol to air. The refractive index of alcohol is 1.36. Calculate the speed of light in alcohol with respect to air.

Answer 1

Given; 

Refractive index of alcohol (μ) = 1.36. 

Speed of light in vacuum = 3×10⁸m/s. 

Refractive index (μ) = \(\frac{c\,(speed\,of\,light\,in\,vaccum)}{v\,(speed\,of\,light\,in\,alcohol)}\)

⇒ 1.36 = \(\frac{3\,\times\,10^8}{speed\,of\,light\,in\,alcohol}\)

⇒ speed of light in alcohol = \(\frac{3\,\times\,10^8}{1.36}\)

∴ Speed of light in alcohol = 2.21 × 10⁸m/s 

Speed of light in alcohol with respect to air is 2.21 x 10⁸ms^-1