Question

A light wave of wavelength 600 nm passes from air into a medium with refractive index 1.5. What is the wavelength of light in the medium?

• A. 400 nm
• B. 450 nm
• C. 500 nm
• D. 600 nm

Hint:

Wavelength of light in a medium = $\lambda/n$, where $\lambda$ is original wavelength and $n$ is the refractive index.

Answer 1

The Correct Option is A

Upon entering a medium with a refractive index \( n \), light's speed and wavelength are reduced, while its frequency is unchanged. The wavelength within the medium is calculated as: \[ \lambda' = \frac{\lambda}{n} \] With the given values: \[ \lambda = 600 \, \text{nm}, \quad n = 1.5 \] The calculation yields: \[ \lambda' = \frac{600}{1.5} = 400 \, \text{nm} \]