Question

Monochromatic light of wavelength $589\, nm$ is incident from air on a water surface. What are the wavelength and speed of refracted light? Refractive index of water is 1.33 .

• A. $4.20 \times 10^{-8}$ and $4.0 \times 10^{7} m / s$
• B. $3.68 \times 10^{-9} m$ and $3.02 \times 10^{7} m / s$
• C. $1.9 \times 10^{-10} m$ and $3.2 \times 10^{8} m / s$
• D. $4.42 \times 10^{-7} m$ and $2.25 \times 10^{ R } m / s$

Answer 1

Answer: (D)

For refracted light (In this process wavelength and speed changes but frequency remains the same)
Wavelength of refracted light $\lambda'=\frac{\lambda}{\mu}$
$=\frac{589 \times 10^{-9}}{1.33}$
$=4.42 \times 10^{-7} m$
Velocity of refracted light $v=\frac{c}{\mu}=\frac{3 \times 10^{8}}{1.33}$
$=2.25 \times 10^{8} m / s$