Question

what is the focal lenght of a plane mirror???

Answer 1

hey friend

A plane mirror can be considered as a spherical mirror of infinite radius of curvature. Focal length is half of radius of curvature and hence it is infinity. You can use the mirror formula also to get the focal length of a plane mirror, where the image distance = − object distance.

Answer 2

As plane mirror is not considered as a spherical mirror . So, it has radius of curvature of infinite length and focus length is half of radius Length so it's focus length is also infinite