Light falling on the surface of an object comes back to the same medium is called Reflection of Light. The angle of incidence is the angle made by the incident ray with the
normal at the point of incidence.
The angle of reflection is the angle made by the reflected ray with the normal at the point of incidence. The normal is a line at right angle to the mirror surface at the point of
incidence.
Laws of Reflection:
When light is reflected from a smooth surface, the angle of incidence and angle of reflection are equal.
•
The incident ray, reflected ray and normal to the surface are in the same plane.
When light falls on a rough surface, it undergoes an irregular reflection. This
is scattered reflection
In the dust particles of the atmosphere, light undergoes scattered reflection. This is scattering
Image formation by Plane Mirror:
Image formed by a plane mirror is always virtual and erect.
•
The size of the image is equal to that of the object. The image formed is as far behind the mirror as the object is in front of it.
•
The image is laterally inverted.

Multiple Reflection and Image Formation
•
The relation between the angle between the mirrors and the number of
images:
360
n
=
-1
Field of View of Mirrors and the Nature of Images
Plane mirror:
• The image is behind the mirror. • Distance to object and distance to image from the mirror are the same. • The image is virtual, erect and is of the same size as that of the object. • Use – For observing the face
Convex mirror
• Image is always formed in between the pole of the mirror and the principal
focus. The image is diminished, virtual and erect.
• Use – Used as rear-view mirror.
Concave mirror:
Position(object) – Position(image) – Image Size – Nature (image):
At infinity
– At F – Highly diminished point-sized – Real and inverted
Beyond C
– Between F and C – Diminished – Real and inverted
At C – At C – Same size – Real and inverted
Between C and F – Beyond C – Enlarged – Real and inverted At F – At infinity – Highly enlarged – Real and inverted

Between P and F – Behind the mirror – Enlarged – Virtual and erect

Mirror equation:

=-+
V
This is known as mirror equation.
New Cartesian Sign Convention:
In all experiments related to lenses and mirrors the distances are measured in the same way as in graphs.
• Distances are measured considering the Pole of the mirror as the origin (O). • Those measured to the right from O are positive and those in the opposite
direction are negative. • Distances measured upwards from X axis are positive and those
downwards are negative. The incident ray is to be considered as travelling from left to right.
Magnification: