Q. 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) $221\ nm$
Explanation
(b) The refractive index of water with respect to air
$\mu = \frac{C_{air}}{C_{water}} = \frac{v\lambda_{air}}{v\lambda_{water}},\ \mu = 1.33$
$\therefore\lambda$ in water $= \frac{\lambda_{air}}{\mu} \Rightarrow \lambda$ in water $= \frac{589}{1.33}nm$
$\Rightarrow \lambda$ in water $= 443\ nm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.