Question

When a ray of light of wavelength \( \lambda \) and frequency \( \nu \) is refracted into a denser medium,

• A. \( \lambda \) and \( \nu \) both increase.
• B. \( \lambda \) increases but \( \nu \) is unchanged.
• C. \( \lambda \) decreases but \( \nu \) is unchanged.
• D. \( \lambda \) and \( \nu \) both decrease.

Hint:

When light refracts into a denser medium, its speed decreases, which leads to a decrease in wavelength. The frequency, however, remains the same.

Answer 1

The Correct Option is C

Step 1: When light enters a denser medium, its speed decreases due to the higher refractive index \( \mu \). The relationship between the speed of light \( v \), wavelength \( \lambda \), and frequency \( \nu \) is given by: \[ v = \lambda \nu \] Since the frequency \( \nu \) remains unchanged when light passes from one medium to another, the decrease in speed \( v \) leads to a decrease in the wavelength \( \lambda \). Step 2: The refractive index \( \mu \) of the denser medium is greater than 1, and since the speed of light decreases in the denser medium, the wavelength also decreases. Conclusion: The wavelength \( \lambda \) decreases while the frequency \( \nu \) remains unchanged.