When a ray of light travels from air to glass and it strikes the surface of separation at 90 degree,then what

When a ray of light travels from air to glass and strikes the surface of separation at a 90-degree angle (perpendicular to the surface), the ray will undergo a phenomenon known as refraction.

Refraction is the bending of light as it passes from one medium (such as air) to another medium (such as glass) due to a change in its speed. This happens because light travels at different speeds in different mediums.

To understand what happens in this scenario, we need to consider Snell's Law, which relates the angles of incidence and refraction to the refractive indices of the two mediums. The refractive index of a medium is a measure of how much it slows down the speed of light compared to its speed in a vacuum.

When a ray of light passes from air to glass at a 90-degree angle, the angle of incidence is 90 degrees. Furthermore, at a 90-degree angle of incidence, the ray will continue along the same path (if the media are the same) or simply reflect back (if the second medium is a mirror-like surface).

However, in the case of refraction, the ray will not continue along the same path. Instead, it will be bent towards the normal, which is an imaginary line perpendicular to the surface of separation between the two mediums at the point of incidence.

In other words, when a ray of light travels from air to glass and strikes the surface of separation at a 90-degree angle, it will not continue along the same path, rather it will be refracted, which means it will be bent towards the normal.

To calculate the exact angle of refraction, you would need to know the refractive indices of air and glass. The angle of refraction can be found using Snell's Law, which states:

n1 * sin(theta1) = n2 * sin(theta2)

Where:
- n1 and n2 are the refractive indices of the initial and final mediums, respectively.
- theta1 is the angle of incidence (in this case, 90 degrees).
- theta2 is the angle of refraction.

By plugging in the known values, you can solve for the angle of refraction and determine the direction the ray will take after entering the glass.