What are Spherical Mirrors ? Two Types of Spherical Mirrors - Concave Mirror and Convex Mirror
What are Spherical Mirrors ?
Most common type of Curved Mirrors are Spherical Mirrors.
Mirrors in which reflecting surface are curved or spherical in shape, is known as Spherical Mirrors.
There are two types of spherical mirrors:
(i) Convex Mirror
(ii) Concave Mirror
Reflecting surface of a mirror can be curved inwards or curved outwards.
Spherical Mirrors which is curved inward is known as Concave Mirror
Spherical Mirrors The one which curved outwards is known as Convex Mirror.
Properties of Concave mirror
• Reflecting surface is curved inwards.
• Converging mirror
Properties of Convex mirror
• Reflecting surface is curved outwards.
• Diverging mirror
Representation of Images formed by Spherical Mirrors using Ray Diagrams.
(i) A ray parallel to the principal axis, after reflection, will pass through the principal focus in case of a concave mirror or appear to diverge from the principal focus in case of a convex mirror.
(ii) A ray passing through the principal focus of a concave mirror or a ray which is directed towards the principal focus of a convex mirror, after reflection, will emerge parallel to the principal axis.
(iii) A ray passing through the centre of curvature of a concave mirror or directed in the direction of the centre of curvature of a convex mirror, after reflection, is reflected back along the same path.
(iv) A ray incident obliquely to the principal axis, towards a point P (pole of the mirror), on the concave mirror or a convex mirror, is reflected obliquely. The incident and reflected rays follow the laws of reflection at the point of incidence (point P), making equal angles with the principal axis.
Ray Diagrams for Images formed by Concave Mirror
Uses of Concave Mirror
(i) Used in torches, search lights and vehicles headlights to get powerful parallel beam of light.
(ii) Concave mirrors are used by dentists to see large image of teeth of patients. (Teeth have to be placed between pole and focus).
(iii) Concave mirror is used as shaving mirror to see a larger image of the face.
(iv) Large concave mirrors are used to concentrate sunlight to produce heat in solar furnace.
Ray Diagrams of Images formed by Convex Mirror
Conclusion:
Uses of Convex Mirror
(i) Convex mirrors are used as rear view mirrors in vehicles because
- they always give an erect though diminished image.
- they have a wider field of view as they are curved outwards.
(ii) Convex mirrors are used at blind turns and on points of merging traffic to facilitate vision of both side traffic.
(iii) Used in shops as security mirror.
Comments