Question

Light enters the air into glass lid with a refractive index 1.5 calculate the speed of light in air is 3 × 10^8

Answer 1

Given:

Speed of light in air = 3×10⁸ m/s

Refractive index of glass = 1.5

To Calculate:

Speed of light in glass

Formula:

μ = sin i/sin r

Solution:

1.5 = (3×10⁸m/s) / sin r

sin r = 2×10⁸m/s

Therefore, the speed of light in glass is 2×10⁸m/s.

Answer 2

Answer:-

• Refractive index of glass=1.5
• Speed of light in air=3×10^8m/s=C
• Speed of light in glass=V=?

According to Snell's law

$\boxed{\sf \mu =\dfrac{C}{V}}$

$\\ \sf\longmapsto 1.5=\dfrac{3\times 10^8}{V}$

$\\ \sf\longmapsto V=\dfrac{3\times 10^8}{1.5}$

$\\ \sf\longmapsto V=2\times 10^8m/s$

Speed of light in glass is 2×10^8m/s.