A symetrical double convex lens is cut in two equal parts by a plane perpendicular to the principal axis .If the power of the original lens is 4D,the power of a cut lens will be..??

1 Answer
Jun 6, 2015

It will become two lenses of +2D each.

So the strength of each part is halved. This means the focal length of each half will be double that of the original lens:
4Dharrf=0.25m and 2Dharrf=0.50m