Question

If speed of light in air is 3*10^8 m/s, then speed of light in a medium of refractive index 3/2 is?

Answer 1

Explanation:

$refractive \: index = \frac{speed \: in \: air}{speed \: in \: medium}$

$\frac{3}{2} = \frac{3 \times {10}^{8} }{speed \: of \: light \: in \: medium}$

$speed \: of \: light \: in \: medium = 2 \times {10}^{8} m/s$

Therefore, it is your answer.

I hope it helps you. If you have any doubts, then don't hesitate to ask.

Answer 2

Answer:

• Speed of light in medium = 2 × 10^8 m/s

Explanation:

Given:

• Speed of light in air, c = 3 × 10^8 m/s
• Refractive index of a given medium, n = 3/2

To find:

• Speed of light in given medium, v =?

Knowledge required:

• The refractive index of a medium with respect to air is given by the ratio of the speed of light in air and speed of light in the given medium.

        n = c / v

[Where n is refractive index of given medium, c is speed of light in air and v is speed of light in given medium]

• The refractive index of any medium with respect to air is called absolute refractive index of medium.

Calculation:

Using formula

→ n = c / v

[ putting known values ]

→ 3/2 = ( 3 × 10^8 ) / v

→ v = 3 × 10^8 × 2 / 3

→ v = 10^8 × 2

→ v = 2 × 10^8  m/s

Therefore,

• Speed of light in the given medium is 2 × 10^8 m/s.