Question

A ray of line enter benzene from air . If the refractive index of benzene is 1.50 , by what percentage does the speed of light really reduce on entering the Benzene ?

Answer 1

A ray of light enters into benzene from air. If the refractive index of benzene is 1.50, by what percent does the speed  of light

Answer: 33.3 %

Explanation:

When the light enters from rarer medium to denser medium, its speed reduces. The ratio of the speed of light in the two media gives the refractive index of the medium.

Refractive index,

 (given for Benzene)

speed of light in air,

Hence, speed of light in the medium,



The percentage of speed of light reduces

Hence, the speed of light reduces by 33.3 % on entering Benzene.

Answer 2

Answer:

33.3 % .

Explanation:

Given :

Refractive index of benzene = 1.50

We know :

Speed of light = 3 × 10⁸ m / sec

We know formula for n :

n = speed of light in vacuum / speed of light in benzene

n = c / v

1.5 = 3 × 10⁸ / v

v = 2 × 10⁸ m / sec

Now ,

Percentage ( % ) decrease = 1  × 10⁸ / 3  × 10⁸  × 100 %

% decrease = 33.3 % .