- Properties of images formed by plane mirror
The image is formed behind the mirror and has the same size as the object
The image is laterally inverted
The image is as far behind the mirror as the object is in front of it.
The images virtual it cannot be received on a screen
The images erect straight up right
- Characteristics of light
Light is an Electromagnetic wave
Light travels in a straight line.
The speed of light waves in vacuum is very high that is 3 x 10 raised to 8
The speed of light depends upon.
The nature of medium speed of light in air is 3 x 10 raised to 8 metre per second speed of light in glass is 2 x 10 raised to 8 metre per second and speed of light in water is 2.25 M into 10 raise to 8 metre per second.
- Reflection of light
reflection is the phenomenon in which light rays on striking a polished surface have sent back into the same medium. There are two types of reflections they are as follows:-
- Regular reflection
A reflection in which parallel beam of light bounces back from highly polished surface as a parallel beam in some other direction is called regular reflection of light.
- Irregular reflection
A reflection in which a parallel beam of light on striking a rough surface gets reflected in various directions in the same medium is called regular reflection of light.
- Laws of reflection
Falls on a smooth reflecting surface it opens the following two laws of reflection:-
The angle of incidence is equal to the angle of reflection.
The incident ray, the normal at the point of incidence and the reflected ray all lie in the same plane.
Note when a Ray of light incident normally that is angle of incidence is equal to zero on mirror fights with the normal as per the laws of reflection that is angle of reflection is equal to zero degree.
- Lateral inversion
If the left of the object becomes right of the image and vice versa this phenomenon is called lateral inversion. Due to lateral inversion to read a text which is reflected by a plane mirror therefore the word ambulance.
On the hospital when is written in form of its Mirror image
Sperical mirror mirror which is obtained by taking a part of hollow sphere of glass or any polished metal is called a spherical mirror
The two types of spherical mirror are as follows
- CONCAVE MIRROR
Concave mirror a spherical mirror reflecting surface is covered inwards is called concave mirror
- CoNvex mirror
A spherical mirror whose reflecting surface is called out words is called convex mirror
- Pole
The centre of the reflecting surface of a spherical mirror is called pole it is denoted by p.
- Aperture
Effective width of getting surface from which reflection of light takes place is called aperture it is denoted by MN.
Centre of curvature centre of the hollow sphere of which spherical mirror is a part is called centre of curvature. It is denoted by c.
The centre of curvature of concave mirror lies in front of it but it lies behind in a convex mirror.
Radius of curvature
Radius of curvature is the radius of hollow sphere of which mirror is a part. It is the distance between the pole and centre of curvature it is denoted by R.
Principal axis
Straight line passing through the centre of curvature and pole of sperical mirror is called the principal axis. Line PC represents the principal axis.
Principal focus if a beam of light parallel to the principal axis falls on a concave mirror all the rays after reflection meet at a point on the principal Axis this point is called principal focus of concave mirror.
in case of a convex mirror a all the race diverge of after reflection . If the reflected rays are extended backwards they appear to come from a point on the principal axis. This point is called principal focus of a convex mirror.
Of concave mirror is in front of the mirror there for concave mirror is called converging mirror.
Mirror live behind the mirror convex mirror is called diverging mirror.
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