Question

The wavelength of light in a medium ‘M’ is 900 nm. If the wave enters a medium ‘N’ of refractive index `4/3`, then its wavelength is:

Options

• 675 nm

• 650 nm

• 695 nm

• 700 nm.

Answer 1

675 nm

Explanation:

The frequency of light remains unchanged during refraction.

Taking the given refractive index as that of medium N,

$$\lambda_N = \dfrac{\lambda_M}{\mu_N}$$

$$= \dfrac{900\ \mathrm{nm}}{4/3}$$

= 675 nm