Monochromatic light of wavelength 600 nm is incident from air on to water surface. The frequency of refracted light is

$5 × 10^{14} Hz$

The correct answer is Option (2) → $5 × 10^{14} Hz$

$\text{Given: Wavelength in air } \lambda_\text{air} = 600~\text{nm}$

$\text{Refractive index of water } \mu \approx 1.33$

$\text{Frequency of light remains unchanged when passing from one medium to another: } f_\text{water} = f_\text{air}$

$\text{Frequency in air: } f = \frac{c}{\lambda} = \frac{3 \times 10^8}{600 \times 10^{-9}}$

$f = 5 \times 10^{14}~\text{Hz}$

$\text{Answer: } f_\text{refracted} = 5 \times 10^{14}~\text{Hz}$