Question

Explain the following terms :

Pole, Centre of curvature, Radius of curvature, Principal axis.

Show them on separate diagrams for each of the concave and convex mirrors.

Answer 1

POLE: “The geometric centre of spherical mirror is called POLE.”
Or
“The mid point of aperture AB of mirror is called pole.”
P is pole of mirror.
CENTRE OF CURVATURE : “Is the centre of hollow sphere of which the mirror forms a part.” It is represented by the symbol ‘ C ‘.
RADIUS OF CURVATURE : “Is the radius of hollow sphere of which the mirror is a part”. It is represented by ‘R’.
PRINCIPAL AXIS: “Is a straight line joining the pole of the mirror to its centre of curvature and extended further.”