Question

The wavelength of light from a source is 3000a in water 2650 in glass and 4000a in vacuum calculate the refractive index of water and glass

Answer 1

c = Speed of light in air → 3 X 10^8 m/s

W → Wavelength

n → Refractive index of the medium = 1.5

W in air = 6000 A = 6 X 10^-7 metres

λ → Frequency in air = c / W in air = 5 X 10^14 Hz

n = W in air / W in the medium

1.5 = 6000 / W in the medium

W in the medium = 4000 A .Magnitude of frequency depends upon the light producing source hence it remains constant throughout ( 5 X 10^14 Hz) .