Question

If light travels from oil (slower medium) to water (faster medium) at an angle, what happens to the direction of the light ray in water with respect to normal?. A. It moves away from the normal. B. It moves toward the normal. C. It will move along the normal. D. It will move perpendicular to the normal. E. It stops traveling.

Answer 1

Refraction is the bending of the direction of light when it travels from a faster medium to slower medium. One example is the illusion of the bending of a pencil underneath water is seen. In this case, light is said to be traveling from slower to faster medium, the reverse is true which is A) light moves away from the normal.

Answer 2

The correct answer is:

A. It moves away from the normal

Step-by-step explanation:

We can answer the question by looking at Snell's law:

`n_1 sin \theta_1 = n_2 sin \theta_2`

where

n1 is the index of refraction of the first medium

n2 is the index of refraction of the second medium

`\theta_1` is the angle between the ray of light and the normal in the first medium

`\theta_2` is the angle between the ray of light and the normal in the second medium

We can re-arrange the equation as follows

`sin \theta_2 = sin \theta_1 (n_1)/(n_2)`

In this problem, light travels from oil to water. Oil is a slower medium than water:: it means that oil has a larger refractive than water, so
`n_1 > n_2`. Therefore, the fraction on the right in the equation is larger than 1, and so we have

`sin \theta_2 > sin \theta_1`

which means

`\theta_2 > \theta_1`

so, the ray of light moves away from the normal.