What is the difference between a plane mirror and a curved mirror?

1 Answer
Oct 12, 2015


"Plane" means flat, so a plane mirror is flat.


Light reflects from a surface with the angle of reflection (compared to a line drawn perpendicular to the surface, which is called the Normal) equal to the angle of incidence, the angle of the incoming light.
graph{|x| [-10, 10, -5, 5]}

In the graph, the y-axis (vertical) represents the Normal. The blue line coming from the left would be the Incident Ray, and the angle formed between the line and the y-axis is called the Angle of Incidence. This is equal to the Angle of Reflection to the right of the Normal.

A Normal drawn on a curved mirror is perpendicular to the surface at the point where it touches. Draw the Normal at another place on the surface of the mirror and you'll see that it points in a different direction.