Which of the following statements is correct with respect to the mirror equation?

The mirror equation is given by:

1/f = 1/v + 1/u

In this equation:

u = object distance

v = image distance

f = focal length

A fundamental rule of the mirror formula is that all these distances must be measured from a common reference point.

For spherical mirrors, the reference point is always the mirror pole (P).

This makes Option B correct.

Why other options are incorrect:

Option A is incorrect because the center of curvature is not “equally spaced”; it is located at a distance equal to the radius of curvature from the pole.

Option C is incorrect because rays do not necessarily strike or deviate at the pole.

Option D is incorrect because the pole and focus are different points; the focus lies at half the radius of curvature.

✔ Therefore, the correct statement is: All distances must be measured from the mirror pole.