Here's the question you clicked on:
vikkisri17
If a biconvex lens is cut along the plane of principal axis, what will be the new power of the lens. Assume original power to be P..
it remains same u got some formula right p = (u-1)(1/r1 - 1/r2) since r1 and r2 dont change it remains same....... if cut vertically um well use the same eqn nd solve it
Principal plane is perpendicular to optical axis. The power will be halved.
See: http://en.wikipedia.org/wiki/Principal_plane#Principal_planes_and_points ans scroll down to 'Principle planes and points'
i agree power wil be halved. . .