Question

A Ray of light enters into benzene from air is the refractive of engine is 1.50 does the speed of light reduce on entering the Benzene

Answer 1

Given:

Refractive index = 1.50

Light enters benzene.

To find:

The reduction in the speed of the light.

Solution:

By formula,

Refractive index = c / v

Where,

c - speed of light in air

c = 3 * 10^8 m / s

v -  speed of light in benzene.

v = c / Refractive index

Substituting,

We get,

v = 3 * 10^8 / 1.50

Hence, the speed of the light in benzene = 2 * 10^8 m / s

Difference in speeds =  3 * 10^8 - 2 * 10^8 / 3 * 10^8

Hence, the speed reduces by 33%

Answer 2

Let c be the speed of light in vacuum.

Let x be the speed of light in benzene.

Then c/x= 1.5

Or, x= c/1.5= 2c/3

Reduction in the speed of light= c-2c/3 =c/3

Percentage of reduction in the speed of light=

c/3/c*100 = 33.33

Ans. There has been a reduction in the speed of light by 33.33% while traveling through benzene whose refractive index is 1.5.