Question

State four differences between refraction of light and total internal reflection of light.

Answer 1

Basis of Difference	Refraction of light	Total internal reflection of light
1. Meaning	Refraction of light is the change in direction of light as it passes from one optical medium to another.	Total internal reflection of light is the complete reflection of light back into the denser medium at the boundary with a rarer medium.
2. Direction of travel	Refraction of light involves light passing into the second medium.	Total internal reflection of light sends the ray back into the original denser medium.
3. Conditions	Refraction of light can occur when light passes between different optical media.	Total internal reflection of light occurs only when light travels from a denser to a rarer medium and the angle of incidence is greater than the critical angle.
4. Light energy	Refraction of light allows some light to pass into the second medium, while some may be reflected at the boundary.	Total internal reflection of light reflects the entire ray back into the denser medium, with no transmitted ray.