Question

What are the rules of refraction?​

Answer 1

Explanation:

• Light bends while travelling from one medium to another only if it is incident on the boundary at an angle to the normal. It does not bend if it is incident perpendicular to the boundary, or along the normal.

• If you imagine a normal to the surface of the water where the beam of light strikes it, you will realise that the Ray of light bends towards the normal as it passes into the water. This observation holds whenever light travels from an optically rarer to an optically denser medium. Light bends towards the normal when it travels from an optically rarer to denser medium.

• If you shine the light at the bottom of the bottle, you will notice that the ray bends away from the normal as it travels from water to air. This too is a general rule. Light bends away from the normal while travelling from an optically denser to rarer medium.

• There is another rule that will become clear. If light follows a certain path while travelling from a point A in one medium to a point B in another medium then it will follow the same path while travelling from B to A. In other words, it will retrace its path.

Answer 2

Snell's law is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air.