Question

define the principal focus of a concave mirror​

Answer 1

Explanation:

Hey mate,

The principal focus of the concave mirror is a point on its principal axis to which all the light rays which are parallel and close to the axis, converge after reflection from the concave mirror.

Hope this will help u

Answer 2

$\huge\underline\mathfrak\green{Answer}$

Principal focus

It is the point on the principal axis of the mirror, where incident rays which is parallel to the principal axis, after reflection from mirror intersect each other

Thank you ❤