A light ray of frequency ' $v$ ' and wavelength ' $\lambda$ ' enters a liquid of refractive index…

A light ray of frequency ' $v$ ' and wavelength ' $\lambda$ ' enters a liquid of refractive index $\frac{3}{2}$ The ray travels in the liquid with
  1. frequency $v$ and wavelength $\left(\frac{1}{2}\right) \lambda$
  2. frequency $v$ and wavelength $\left(\frac{2}{3}\right) \lambda$
  3. frequency $\left(\frac{3}{2}\right) v$ and wavelength $\lambda$.
  4. frequency $v$ and wavelength $\left(\frac{3}{2}\right) \lambda$

Solution

The problem involves a light ray of frequency $\nu$ and wavelength $\lambda$ entering a liquid of refractive index $n$. The refractive index affects the wavelength of the light as it enters the liquid, but the frequency remains unchanged. The wavelength in the liquid is given by: $\lambda_{\text {liquid }}=\frac{\lambda_0}{n}$ where $\lambda_0$ is the wavelength in the air or vacuum, and $n$ is the refractive index of the liquid. So, the light ray will travel in the liquid with the same frequency and a shortened wavelength. Thus, the correct answer is: (2) frequency and wavelength .

Asked in: MHT CET 2020 (12 Oct Shift 2)

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