ICSE

A virtual image is one in which the light rays do not really pass through the image point but appear to diverge from that point.

A real image is one in which light rays actually intersect or pass through the image point.

An image is a point or plane to which rays are converged or from which they appear to diverge after the reflection or refraction of light.

The size of the mirror is called its aperture.

The distance between the pole and the focus is called the focal length.

A plane drawn perpendicular to the principal axis and passing through the principal focus.

It is a point on the principal axis at which the rays parallel to the reflection or seem to come from.

The straight-line passing through the pole and the centre of curvature of the mirror is called the principal axis.

The radius of the sphere of which a mirror is a part is called the radius of curvature.

The centre of the sphere of which the mirror is a part is called the centre of curvature.