The angle of refraction is also 50 degree because of the Law of Refraction.It states that
• The angle of Incidence is equal to the angle of refraction of given two transparent media.
• The sine of angle of Incidence to the sine of angle of Refraction is constant for a light of given colour and for a pair of given media.

Angle of Incidence and Refraction

When a ray of light passes through two different media, it changes its direction. The angle at which the light ray strikes the surface is called the angle of incidence, and the angle at which it bends or changes direction is called the angle of refraction.

Snell's Law

The relationship between the angle of incidence and the angle of refraction is given by Snell's law, which states that:

n1 sin θ1 = n2 sin θ2

Where n1 and n2 are the refractive indices of the two media, and θ1 and θ2 are the angles of incidence and refraction, respectively.

Calculating the Angle of Refraction

In this problem, the ray of light is passing from air to water. The refractive index of air is 1, and the refractive index of water is 1.33. The angle of incidence is given as 50 degrees.

Using Snell's law, we can calculate the angle of refraction as follows:

n1 sin θ1 = n2 sin θ2

1 sin 50 = 1.33 sin θ2

sin θ2 = (1 sin 50)/1.33

θ2 = sin^-1 [(1 sin 50)/1.33]

θ2 = 34.8 degrees

Therefore, the angle of refraction is 34.8 degrees.

Explanation

When a ray of light passes from air to water, it bends towards the normal (a line perpendicular to the surface of the water). This is because water has a higher refractive index than air, which means that it slows down the speed of light. As a result, the light ray changes direction and bends towards the normal.

The angle of refraction is always smaller than the angle of incidence when light passes from air to water, as the light ray bends towards the normal. In this problem, the angle of refraction is 34.8 degrees, which is smaller than the angle of incidence of 50 degrees.