Final answer:
When a ray of light travels from an optically denser medium to a rarer medium, it A. bends away from the normal due to refraction, as light speeds up in rarer media. This can be explained by Snell's Law.
Step-by-step explanation:
When a ray of light travels from an optically denser medium to a rarer medium, it bends away from the normal, which is the imaginary line perpendicular to the surface between the two media. This phenomenon occurs because the light increases its speed when it moves from a medium with a higher refractive index to a medium with a lower refractive index. An example of this is when a ray of light exits from water to air; it deviates away from the normal because air is less optically dense than water.
Refraction is the principle that determines this change in direction, and it is portrayed by Snell's Law. This law states that the ratio of the sines of the angles of incidence and refraction is equivalent to the ratio of the indices of refraction of the two media. As the light increases in speed, the wavelength increases, but the frequency remains constant.
SUMUP all the final answer as points:
- The ray of light deviates away from the normal when going from denser to rarer medium.
- Light speed increases and the wavelength increases, frequency remains constant.
- Refraction causes light to bend, guided by Snell's Law.