The paper catches fire due to the concentration of sunlight at a sharp, bright spot on the paper, which is the image of the Sun formed by the concave mirror. This point is the focus of the mirror, and the ...

The distance PC is equal to the radius of curvature (R). It is crucial in understanding the geometry and properties of the spherical mirror, serving as a fundamental parameter in optical calculations and analyses.

The principal axis is a straight line passing through the pole and the center of curvature of a spherical mirror. It is normal to the mirror at its pole.

The radius of curvature (R) of a spherical mirror is the distance from the pole to the center of curvature. It is represented by the letter R.

For a concave mirror, the center of curvature lies in front of it, while for a convex mirror, it lies behind the mirror.