Question

when a light ray travels from denser to rarer medium ,then the angle of incidence for which the angle of refraction becomes is 90degree is called as​

Answer 1

Answer:

angle of incidence is equal to 90 degree

Answer 2

The angle of incidence for which the angle of refraction becomes is 90° is called as the critical angle.

• When a light ray travels through two mediums with different density, the refraction of that light ray, takes place.
• Similarly, when a light ray travels from optically denser to optically rarer medium, the refraction also takes place. In this case, the light ray bends away from the normal,in certain angle. This bending angle is known as the refraction angle.
• And, for a particular angle of incidence the angle of refraction becomes 90°. This particular angle is popularly known as the "critical angle".
• The value of the critical angle is dependent on the refractive index of the two mediums.