Mirrors
A
mirror is a surface that can reflect a beam of light in one direction
instead of either scattering it widely in many directions or absorbing it. A
shiny metal surface acts as a mirror; a concrete wall does not. Considering
plane mirrors as the base we can derive the equation regarding the image
formed.
A point source of
light O is considered, which is called the object, at a perpendicular distance
‘’ in front of a
plane mirror. The light that is incident on the mirror is represented with rays
spreading from O. The reflection of that light is represented with reflected
rays spreading from the mirror. If we extend the reflected rays backward
(behind the mirror), we find that the extensions intersect at a point that is a
perpendicular distance ‘’ behind the
mirror. The image point I is of the object O .It is called a point image
because it is a point, and it is a virtual image because the rays do not
actually pass through it.
Mirrors are of two type:
·
Concave mirrors
·
Convex mirrors
Concave mirror:
It is a spherical mirror which
when looked from the reflecting side is depressed at the center and bulging at
the edges.
Convex mirror:
It is a spherical mirror which
when looked from the reflecting side bulges at the center and is depressed at
the edges
.