Question

Spherical vs Parabolic Mirrors. By drawing accurate diagrams, explain exactly why spherical mirrors do not bring incoming parallel rays of light to a sharp focus, but parabolic mirrors do.

Answer 1

Hi buddy!

Here is the answer to your question!

Parabolic mirrors differ from spherical mirrors in shape of the mirror.

Sperical mirrors are perfect round where as parabolic mirrors do not follow a perfect curve and represent that of a parabola.

This explains why the focus is not as sharp in spherical mirrors as in the case of parabolic mirrors.

Parabolic mirrors focus parallel rays into a single point, but a spherical mirror (which has a circular shape) only focuses at a point when the object is at the center of the curvature.

.For objects at a distance, the spherical mirror only approaches the focus at one point as the section gets very small and it acts like a paraboloid. Refer the attached picture to get an idea of the difference between the two types of mirrors.