Question

Whenever light travels from rarer medium into denser medium its

• A. frequency increases
• B. wavelength increases
• C. frequency decreases
• D. wavelength decreases
• E. wavelength remains unchanged

Hint:

When light passes from a rarer to a denser medium, its wavelength decreases, but the frequency remains constant.

Answer 1

The Correct Option is D

When light travels from a rarer medium to a denser medium, its speed decreases. Since the frequency of light remains constant when it enters a new medium, its wavelength decreases. 
The relationship between the speed \( v \), frequency \( f \), and wavelength \( \lambda \) is given by: \[ v = f \lambda \] 
Since the frequency remains constant and the speed decreases in a denser medium, the wavelength must decrease. 
Hence, the correct answer is (D).