Question

define the principal focus of a concave mirror

Answer 1

convex lens is thicker at the centre than at the edges. ... When parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus. The distance between the principal focus and the centre of the lens is called the focal length.

Answer 2

$\underline {\Huge\mathcal {Answer :-}}$

The principal focus of a concave mirror is a point on the principal axis where rays of light in a direction parallel to the principal axis meet after reflection from the mirror.

$\underline {\Huge \bold {Important \:Terms :-}}$

♣ Reflection : It is the phenomenen of bouncing back of light in the same medium on striking the surface of any object.

♣ Concave Mirror : Concave mirror is a spherical mirror whose reflecting surface is curved inwards, that is, faces towards the centre of the sphere.

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