CONVEX MIRROR:-
Well first off, convex mirrors are diverging mirrors, which means when they reflect light rays, the light rays never meet. The image that forms when an object is any length away from the mirror, the image is VIRTUAL and erect, the height of the image is smaller than that of the object, and the image is always between the focal point and the vertex of the mirror. Hope that helped!
CONCAVE MIRROR:-
Properties of Concave Mirrors
Concave Mirror – A mirror whose reflecting surface curves inwards, like the inside surface of a basketball. You can remember it because the surface of the mirror forms a cave.
Centre of Curvature (C) – The centre of curvature is the centre of the circle formed by the surface of the mirror. If you took a normal line at each point on the mirror, they would meet at the centre of curvature.
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| | You can also find “C” because C = 2f or C = 2 x focal point | |
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Principle Axis – With a concave mirror the principle axis is a line that passes from a point on the mirror through the centre of curvature. For our purposes we will always draw it in the middle of the mirror
Vertex – The Vertex is where the principle axis strikes the mirror.
Focal Point – When a ray travels parallel to the principle axis, it is always reflected through the focal point of the mirror. The distance between the focal point and the surface of the mirror is the focal length. This length is ½ the distance to the centre of curvature.
Images always form where reflected rays from the object meet.
1. Draw a ray parallel to the principle axis and the point on the object. It will reflect through the focal point.
2. Draw a line through the focal point and the point on the object. It will reflect parallel to the principle axis.
3. Draw a line through the centre of curvature and the point on the object. It will reflect back on itself.
- Draw a line through the vertex and the point on the object. Its angle of reflection will be the same as the angle of incidence.
Don’t forget: you can always extend your reflected rays behind the mirror as Virtual Rays.
You must always report the L.O.S.T. characteristics of every image you form. For the image we just created:
L:
O:
S:
T:
You will notice that the image has formed with Real Rays, as opposed to Virtual Rays. This means the image formed is Real Image. Real images can be projected onto a screen.
Concave mirrors will create different images depending on the location of the object.