# The refractive index of water is 1.33. The speed of light in water is? (a) 4 x 108 m/s (b) 3 x 108 m/s (c) 2.25 x 108 m/s (d) 1.33 x 108 m/s

By Ritesh|Updated : November 14th, 2022

The refractive index of water is 1.33. The speed of light in water is 2.25 x 108 m/s.

We know that, μ = c/v = speed of light in air/ speed of light in the medium

Therefore: μv = c

On rearranging we get v = c/μ

Substituting the values we get:

= 3 x 108 m/s/ 1.33 = 2.25 x 108 m/s

### Speed of Light

1. The rate of change of light displacement is known as the speed of light or the speed of light in a vacuum.
2. It is a fundamental constant in many branches of physics.
3. The precise value of light's vacuum speed is 299792458 m/s.
4. When calculating, it is frequently predicated to be 3 x 108 m/s.
5. The thing that moves the fastest on earth is light.
6. Light speed applies to all electromagnetic radiation types.

Refractive Index Formula

There are no dimensions to refractive indices. It measures how much slower than in a vacuum a light wave would flow through a substance. By dividing the speed of light in a medium by the speed of light in a vacuum, the refractive index, denoted by the symbol n, is calculated. The following is the refractive index formula:

n = c/v

Where,

• n = refractive index
• c = velocity of light in a vacuum ( 3 × 108 m/s)
• v = velocity of light in a substance

Summary:

## The refractive index of water is 1.33. The speed of light in water is?(a) 4 x 108 m/s(b) 3 x 108 m/s(c) 2.25 x 108 m/s(d) 1.33 x 108 m/s

The refractive index of water is 1.33. The speed of light in water is 2.25 x 108 m/s. The speed of light through glass is slower than the speed of light through water because glass has a higher refractive index than water.