Question

When light propagates through two adjacent materials that have different optical properties, some interesting phenomena occur at the interface separating the two materials. For example, consider a ray of light that travels from air into the water of a lake. As the ray strikes the air-water interface (the surface of the lake), it is partly reflected back into the air and partly refracted or transmitted into the water. This explains why on the surface of a lake sometimes you see the reflection of the surrounding landscape and other times the underwater vegetation.These effects on light propagation occur because light travels at different speeds depending on the medium. The index of refraction of a material, denoted by n , gives an indication of the speed of light in the material. It is defined as the ratio of the speed of light c in vacuum to the speed v in the material, or

n=cv
A.When light propagates from a material with a given index of refraction into a material with a smaller index of refraction, the speed of the light

Answer 1

The speed of the light increases.

Step-by-step explanation:

If the light moves from a denser medium to a lower density medium, the light moves away from normal. And since the velocity is defined as inversely proportional to the refractive index, the velocity in the medium with more density increases. This can be explained as follows:

`n_(2) <n_(1) \\n=(c)/(v) \\n\alpha (1)/(v) \\v_(2) >v_(1)`

Where n is the refractive index and v is the velocity.

Answer 2

The speed of the light reduces

Step-by-step explanation:

A material with the lesser index of refraction has a lesser relative speed (when compared to speed of light in vacuum) to that with a higher refractive index.