What happens when a light ray strikes a mirror?
When a ray of light strikes a mirror,it is reflected in a different direction
What is Incident Ray and Reflected Ray?
The light ray which strikes a surface is called Incident Ray
The light ray which comes back from surface after reflection is called Reflected Ray
What is Normal
It is a line which is perpendicular to mirror at point of incidence
How to Draw Normal
Let Mirror be denoted by AB
Let Point where incident ray strikes mirror be O
We draw a line ON which is perpendicular to mirror AB at point O
This ON is called Normal Ray
What is the Angle of Incidence and Reflection?
Angle between Normal and Incident Ray is called Angle of Incidence
Let it be denoted by i
Angle between Normal and Reflected Ray is called Angle of Reflection
Let it be denoted by r
Angle of Incidence is always equal to the Angle of Reflection
In our case,
Angle i = Angle r
Laws of Reflection
There are 2 laws of Reflection
- The Incident ray, Reflected ray and the Normal, all lie in the same plane
- The Angle of Incidence is always equal to Angle of Reflection
So, in our figure above,
Incident ray OP, reflected ray OQ and Normal ray ON all lie on the same plane
Angle of incidence = Angle of Reflection
Check the figure below
In this figure, the incident ray, reflected ray and normal all lie on the table. So, they all lie on the same plane.
And, Angle of Incidence = Angle of Reflection.
Check out the video below for the full experiment