Question

Find the time taken by light to travel 300 metres in diamond

Answer 1

Speed of light in vacuum=3×10⁸m/sec

Given refractive index of Diamond(n)=2.5

Let the speed of light in Diamond be'x'm/sec.

We have, 

Refractive index=Speed of light in vacuum/Speed of light in medium

⇒2.5=3×10⁸/x

⇒x=3×10⁸/2.5

⇒x=1.2×10⁸ m/sec

Therefore, the speed of light in Diamond=1.2×10⁸m/sec