Question

what is the value of radius of curvature in plane mirror

Answer 1

Radius of curvature is the radius of the imaginary sphere of which the mirror is a part.

You can easily find the radius of curvature of a spherical mirror.

But there is no curvature in plane mirror. So what is its curvature?
If you observe carefully, as you decrease the curvature of the spherical mirror, the radius of curvature increases. If you go on decreasing the curvature, the radius of curvature goes on increasing.
If you decrease the curvature enough, you will get a straight line with no curvature (plane mirror are straight). Here, the radius of curvature becomes infinite.

So, for a plane mirror, the radius of curvature is infinity.

$\boxed{ \textbf{ \red{ radius of curvature = infinity}}}$

Answer 2

it is undefined
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