When going from an optically less dense medium to a more optically dense medium (such as air to water), how does the angle of in
cidence compare with the angle of refraction? Does the light bend towards or away from the normal? What about from a more-dense medium to a less-dense medium (water to air)?
When light goes from an optically rarer medium to an optically more dense medium, the bending of light takes place towards the normal.
In case, the light travels from air, i.e., less dense to water, i.e., optically more dense, then in accordance to Snell's law, the medium with the lower refractive index will have the larger angle whereas the medium with higher refractive index will have smaller angle.
Also, as light travels from a an optically less dense to optically more dense medium, speed of light reduces and hence its wavelength while the frequency remains intact.
Converse is true when light travels from an optically more denser to optically less dense medium, the light bends away from the normal, like in case of water to air, where water is comparatively more dense
The answer is wave B has a lower frequency. Suppose these waves represent the sound of a siren on a passing ambulance. Wave B (lower frequency) represents the sound of the siren after it has passed you. The ambulance moving towards the observer produces a higher than normal frequency, and the ambulance moving away produces a lower than normal frequency.
