Question

In total internal reflection angle of incidence inside the material increases the angle of refraction and it increases to a point at which it leaves the material at ___.

• A. ${90}^{\circ }$.
• B. ${180}^{\circ }$.
• C. ${270}^{\circ }$.
• D. ${360}^{\circ }$.

Answer 1

The correct option is A ${90}^{\circ }$.

When light travels from an optically dense medium to a less dense medium, the light will bend away from the normal. If the angle of incidence is gradually increased, the refracted ray deviates so far away from the normal that it reflects rather than refracts. The angle of incidence inside the material increases the angle of refraction and it increases to a point at which it leaves the material at ${90}^{\circ }$.