Question

What sign conventions are used for reflection from a spherical mirror?

Answer 1

Sign Conventions for spherical Mirrors:

I. Objects are always placed to the left of the mirror i.e. light must fall on the mirror from left to right.

II. All distances are measured from the pole of the mirror.

III. Distances along the direction of the incident ray (along the positive x-axis) are taken as positive, while distances along the direction of the reflected ray (along the negative x-axis) are taken as negative.

IV. Heights measured perpendicular to and above the principal axis (along the positive y-axis) are taken as positive.

V. Heights measured perpendicular to and below the principal axis (along the negative y-axis) are taken as negative.

These sign conventions can also be represented in the following diagram: