Question

b.when a ray of light enters from air to glass, the refractive index is
1.5. If the speed of light in air is 3 x 10^8 m/ sec.what is the speed of
light in glass ??​

Answer 1

b.when a ray of light enters from air to glass, the refractive index is

1.5. If the speed of light in air is 3 x 10^8 m/ sec.what is the speed of

light in glass

Answer 2

Given :

• When a ray of light enters from air to glass, the refractive index is 1.5.
• The speed of light in air is 3 x 10⁸ m/s.

To Find :

The speed of light in glass.

Solution :

Analysis :

Here we have to use the refractive Index formula.

Required Formula :

Refractive Index(μ) = Speed of light is vaccum or air/Speed of light in that medium

Units :

• μ = no units because it us a ratio
• Speed of light in air = m/s
• Speed of light in glass = m/s

Explanation :

The refractive index is denoted by μ.

We know that if we are given the refractive Index then our required formula is,

Refractive Index(μ) = Speed of light in air/Speed of light in glass

where,

• μ = 1.5
• Speed of light in air = 3 x 10⁸ m/s

Using the required formula and substituting the required values,

⇒ μ = Speed of light in air/Speed of light in glass

⇒ 1.5 = 3 x 10⁸/Speed of light in glass

⇒ Speed of light in glass = 3 x 10⁸/1.5

⇒ Speed of light in glass = 3 x 10⁸ × 10/15

⇒ Speed of light in glass = 10⁸ × 10/5

⇒ Speed of light in glass = 10⁸ × 2

⇒ Speed of light in glass = 2 × 10⁸

∴ Speed of light in glass = 2 × 10⁸ m/s.

The speed of light in glass is 2 × 10⁸ m/s.

Explore More :

The refractive index of second medium with respect to the first medium is defined as the ratio of sine of angle of incidence in the first medium to the sine of angle of refraction in the second medium.

It is denoted by the greek letter mu(μ).