Question

what is the power of a plane mirror

Answer 1

the focal length of mirror is infinity, it's optical power is zero.

hope this may help u.

thnx. ❤

Answer 2

since the focal length of a plane mirror is infinity, the power is the reciprocal of focal length. therefore it is zero.

(the focal length is infinity because rays parallel to the principle axis continue to be parallel even after reflection. so they are considered to meet at infinity.)