Question

The speed of light in a vacuum is approximately 2.99 × 108 m/s, and the speed of light through a piece of glass is approximately 1.97 × 108 m/s.

What is the index of refraction for the piece of glass?

a) 0.66
b) 1.52
c) 1.02 × 10^8
d) 4.96 × 10^8

Answer 1

Option (b) is correct.The index of refraction for the glass is 1.52

Explanation:

velocity of light in vacuum= C= 2.99 x 10⁸m/s

Velocity of light in glass = V= 1.97 x 10⁸m/s

The refractive index is given by n=$\frac{c}{v}$

n= 2.99 x 10⁸/1.97 x 10⁸m/s

n= 1.52

Thus the refractive index of glass is 1.52

Answer 2

Answer:

The index of refraction for the piece of glass is 1.52

Explanation:

Given that,

Speed of light in vacuum, $c=2.99\times 10^8\ m/s$

Speed of light through a piece of glass is, $v=1.97\times 10^8\ m/s$

The ratio of speed of light in vacuum to the speed of light in a medium is called refractive index i.e.

$n=\dfrac{c}{v}$

$n=\dfrac{2.99\times 10^8}{1.97\times 10^8}$

n = 1.52

Hence, the index of refraction for the piece of glass is 1.52