Why no refraction takes place at angle of incidence equal to 90 degrees

Asked by B P | 19th Mar, 2017, 04:25: PM

Expert Answer:

Refraction takes place because the speed of light is different in different media. Now, this change takes place when light is incident at an angle.
Light always travels along a straight line and along the shortest path. When speed changes light has to bend in order to take the shortest path possible.
But, when light is incident at 0° (Angle of incidence is w.r.t. normal. So, it should be 0°) the shortest path after refraction is that same vertical line. Hence, light does not bend and no refraction takes place.

Answered by Romal Bhansali | 20th Mar, 2017, 09:37: AM