When monochromatic light passes from vacuum into a medium of refractiv…

Question

When monochromatic light passes from vacuum into a medium of refractive index $\mu$:

Accepted Answer

C. Frequency stays the same, wavelength becomes $\lambda/\mu$

Frequency is set by the source and cannot change at an interface. Speed in the medium is $v = c/\mu$, so $\lambda' = v/
u = (c/\mu)/
u = \lambda/\mu$. The wavelength shrinks in a denser medium while colour (frequency) is preserved.

Answer

Both frequency and wavelength decrease

Answer

Frequency decreases, wavelength stays the same

Answer

Both frequency and wavelength stay the same