Image Formation by Spherical Mirrors
The position, size, and nature of the image formed by a spherical mirror depend on the position of the object relative to the mirror. Let's explore how images are formed in concave and convex mirrors.
Concave Mirror Image Formation
The image formed by a concave mirror depends on where the object is placed:
- Object beyond C: Real, inverted, diminished image between F and C
- Object at C: Real, inverted, same size image at C
- Object between C and F: Real, inverted, enlarged image beyond C
- Object at F: Image at infinity
- Object between F and P: Virtual, upright, enlarged image behind the mirror
Object Position
NearFar
Object between C and F
Ray Diagram Method
To locate the image formed by a spherical mirror, we can use any two of the following rays:
- Ray 1: A ray parallel to the principal axis - after reflection, it passes through (or appears to come from) the focal point
- Ray 2: A ray passing through (or directed towards) the center of curvature - it is reflected back along the same path
- Ray 3: A ray passing through (or directed towards) the focal point - after reflection, it becomes parallel to the principal axis
- A ray incident at the pole - it is reflected according to the law of reflection