Question

Define dispersion of light. How is the focal length of a spherical mirror related

to its radius of curvature? ​

Answer 1

Answer:

In other words, in the small-angle approximation, the focal length f of a concave spherical mirror is half of its radius of curvature, f=R2.

The distance from the pole to the center of curvature is called the radius of curvature (r). The distance from the pole to the focal point is called the focal length (f). The focal length of a spherical mirror is then approximately half its radius of curvature.

The phenomenon of splitting of visible light into its component colours is called dispersion. Dispersion of light is caused by the change of speed of light ray (resulting in angle of deviation) of each wavelength by a different amount.

Note: White light comprises of seven visible colours (VIBGYOR) whereas black (or dark) signifies the absence of light rays.