Question

find the refrective imdex of a glass if light travels in it with a speed of2×10power8 m/s(speed of light in vacum is 3×10power8 m/s​

Answer 1

Given:-

• Speed of light in Glass ,v = 2 × 10⁸ m/s

• Speed of light in air ,c = 3 × 10⁸ m/s

To Find:-

• Refractive index ,ng

Solution:-

We have to calculate the refractive index of a glass .

Using Snell's Law

• ng = c/v

where,

ng is the refractive index

c is the speed of light in air

v is the speed of light in glass

Substitute the value we get

→ ng = 3×10⁸/2×10⁸

→ ng = 3/2

→ ng = 1.5

Therefore,the refractive index of glass is 1.5

Answer 2

Answer:

Given :-

• Speed of light in glass = 2×10⁸ m/s
• Speed of light in vaccum = 3×10⁸m/s

To Find :-

Refractive index

Solution :-

Here we will use the Snell's law.

$\huge \tt \: ng = \frac{c}{v}$

Here,

ng = refractive index

c = Speed of light in vaccum

v = Speed of light in glass

$\sf \: ng \: = \dfrac{3 \times 10 {}^{8} }{2 \times {10}^{8} }$

$\sf \: ng \: = \dfrac{3}{2}$

$\sf ng \: = 1.5$

Hence :-

Refractive index = 1.5