Please explain the second law of reflection.

angle of incidence = angle of reflection

 i =r

The second law of reflecton states that the angle of reflection is always equal to the angle of reflection. The red line in the picture indicates the normal drawn to the point of incidence anhe angle formed between the normal and incident ray is the angle of incidence and the angle formed between the normal and reflected ray is the angle of reflection.

 Thank you amritha and varshini ( I gave a thumbs up to both of you)

 But i am sorry , that is the 1 st law of reflection. I want the second law

Incident Ray:
The ray which comes from the source and travels toward the mirror.

Reflected Ray:
The ray which strikes the mirror and travels towards the observer.

Angle of Deviation:
The angle formed by the incident ray and the reflected ray.

Normal:

·  A perpendicular to a mirror

·  originates at the point of incidence of the light

·  which divides the angle of deviation into two equal parts.

Angle of incidence :
The angle formed by the incident ray and the normal.
Angle of reflection:
The angle formed by the reflected ray and the normal.

Laws of reflection

First Law of Reflection:
The incident ray, the reflected ray, and the normal all lie on the same plane.

Second Law of Reflection:
The angle of incidence is equal to the angle of reflection.

• it means that angle of incidence is equal to angle of reflection

suppose the angle of incidence is 60 degree the the angle of reflection will also be 60 degree. Thus the angle of incidence is always equal to the angle of reflection.

Place a mirror on a table so that the reflective surface is perpendicular to the table top.

Place a book on the table as well, on end and perpendicular to the mirror, so that the mirror and book form a T shape. Leave a small gap between the book and the mirror's surface.

Place a small standing object, like a marker, on one side of the book/mirror set up.

Look through the mirror on the other side of the book so that you can see the image of the marker.

The book acts as the normal line, the incident ray is the ray of light from the marker to the mirror and the reflected ray is the ray of light from the mirror to your eye.

All three must be in the same place, which is parallel to the plane of the table, on order for you to see the image.

Remember that 3 non-colinear points define a plane just as 2 points define line. Your eye, the point of incidence of the light rays with the mirror and the marker are three points in space. Therefore, they define a unique plane.