Class 10 Physics



Reflection from spherical mirror:

Reflection of Rays parallel to Principal Axis:

In the case of concave mirror: A Ray parallel to principal axis passes through the principal focus after reflection from a concave mirror.

parallel rays concave mirror

Fig: Rays parallel to principal axis

Similarly, all parallel rays to the principal axis pass through the principal focus after reflection from a concave mirror. Since, a concave mirror converge the parallel rays after reflection, thus a concave mirror is also known as converging mirror.


In the case of convex mirror: A ray parallel to principal axis appears to diverge from the principal focus after reflecting from the surface of a convex mirror.

parallel rays convex mirror

Fig: Rays parallel to principal axis

Similarly, all rays parallel to the principal axis of a convex mirror appear to diverge or coming from principal focus after reflection from a convex mirror. Since, a convex mirror diverges the parallel rays after reflection, thus it is also known as diverging mirror.

Reflection of ray passing through the Principal Focus:

In the case of concave mirror: Ray passing through the principal focus goes parallel to principal axis after reflection in the case of concave mirror.

rays passing principal focus concave mirror

Fig: Ray passing through principal focus

In the case of convex mirror: A ray directed towards principal focus goes parallel to principal axis after reflecting from the surface of a convex mirror.

rays passing through principal focus convex mirror

Fig: Ray through principal focus


Ray passing through the Centre of curvature:

In the case of concave mirror: Ray passing through the centre of curvature returns at the same path after reflecting from the surface of a concave mirror.

rays passing centre of curvature concave mirror

Fig: Ray passing through C<

In the case of convex mirror: Ray appears to passing through or directed towards the centre of curvature goes parallel to the principal axis after reflecting from the surface of a convex mirror.

rays passing centre of curvature convex mirror

Fig: Ray passing through C

Ray incident obliquely to the principal axis: Ray obliquely to the principal axis goes obliquely after reflecting from the pole of the both concave and convex mirror and at the same angle.

rays passing obliquely to principal axis concave mirror
rays passing obliquely to principal axis convex mirror

Fig: Ray passing obliquely to principal axis