Reflection and spherical mirrors

1. REFLECTION OF LIGHT IN
SPHERICAL MIRRORS
Presented by
Sana

2. WHAT IS REFLECTION OF LIGHT?
❑ when a ray of light falls on a smooth surface and
It bounces back ,this is reflection of light.
❑ Reflection of light enables us to see our beautiful
world around us

3. LAWS OF
REFLECTION
incident ray, reflected ray and the
normal at the point of incidence are in
the same plane.
The angle of incidence is always equal
to angle of reflection.

4. WHY??

5. SMOOTH CURVED SURFACES
Images are formed not only on plane mirrors but also on smooth curved surfaces.

6. SPHERICAL MIRRORS
❑Spherical mirrors are mirrors in which the reflecting surface is a part of the sphere.
❑There are two types of spherical mirrors . They are Concave mirrors and convex
mirrors.

7. CONCAVE MIRROR
It is a type of spherical mirror in which Reflecting surfaces are curved inwards.
It is similar to inner surface of a spoon.

8. CONVEX MIRROR
Convex mirrors are mirrors in which the reflecting surfaces are curved outwards
Similar to outer surface of a steel spoon.

9. TERMS RELATED TO SPHERICAL
MIRRORS
Centre of curvature
• Centre of a sphere of which the mirror
is a part, is the Centre of curvature of
the mirror.
• Any line drawn from the centre of
curvature to the mirror is normal to the
mirror.
Radius of curvature
• Radius of curvature (R) of a mirror is
the radius of the sphere of which it is a
part.
• Distance from the centre of curvature
to the reflecting surface of a mirror is
the radius of curvature.

10. APERTURE
Aperture of a mirror is the reflecting
surface of the mirror.
POLE
Pole of a mirror is the midpoint of the
reflecting surface of the mirror. It is
represented as P
PRINCIPAL AXIS
Principal axis of a mirror is the straight
line connecting the pole of the mirror
and the centre of curvature of the
mirror.

11. FOR A CONCAVE MIRROR
❖Centre of curvature – C
❖Radius of curvature ( R)- AC,CP,CB
❖Pole – P
❖Principal axis – a line through C and P

12. REFLECTION FROM
A SPHERICAL
MIRROR
❑ Incident ray, reflected ray and the normal at
the point of incidence are in the same plane.
❑ Angle of incidence and angle of reflection
are equal in spherical mirrors.

14. FOCUS OF CONCAVE MIRROR
❑ Rays of light incident on a concave mirror, parallel to the principal axis, passes
through a fixed point on the principal axis after reflection. This point is the principal
focus (F) of the concave mirror.

15. PRINCIPAL FOCUS OF CONVEX
MIRROR
❑ Rays of light incident on a convex mirror parallel to the principal axis appear to
come from a fixed point on the other side of the mirror.This point is the principal
focus of the convex mirror.

16. THANK YOU