Question

a ray of light enters into benzen from air if the refrective index of benzene is
1.50, by what percent does the speed of light reduce on entering the benzene

Answer 1

speed in benzene will be the speed of light in air divided by the refractive index in benzene
And then calculate the difference between them

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 % .