Question

Monochromatic light of wavelength $589\, nm$ is incident from air on a water surface. The refractive index of water is $1.33$. The wavelength of the refracted light is

• A. 589 nm
• B. 443 nm
• C. 333 nm
• D. 221 nm

Answer 1

Answer: (B)

The refractive index of water with respect to air
${ }_{a} \mu_{w}=\frac{\mu_{w}}{\mu_{a}}$
$=\frac{\mu \lambda_{\text {air }}}{v \lambda_{\text {water }}} $
$\therefore \lambda $ in water $=\frac{\lambda_{\text {air }}}{\mu}$
$\Rightarrow \lambda$ in water $=\frac{589}{1.33} n m$
$\Rightarrow \lambda$ in water $=443\, nm$