Question

As light travels from a rarer to a denser medium it will have
wavelength​

Answer 1

Answer:

The wavelength will not change it's velocity changes, so denser the medium slower it travels.

Answer 2

Answer:

As light travels from the rarer to denser medium its speed decreases thus the wavelength also decreases. but the frequency remains the same

Explanation:

The wavelength shrinks with reduction in velocity based on the refractive index of the denser medium. This also keeps the frequency of light the same as f = c/w, where c is the speed of light, w is the wavelength, and f is the frequency of light. The frequency stays the same. Light of a certain frequency does not transmutate to another frequency and change color while it is passing through a denser medium ! Remember the color of light is determined by its frequency strictly speaking ! So in a denser medium the wavelength shrinks with the reduction in velocity sumulataneously to maintain the frequency the same ! You can think of it from the great classical physics angle for the purpose of understanding, as an advancing line of particles that encounters resistance and slows down(velocity decrease) with the particles getting also more crowded together due to the imposed inherent impedance to movement through a denser medium, resulting in the wave peaks coming closer together(wavelength shortening) at the same time with no change in frequency .