A biconvex lens of focal length 10 cm is cut into two identical parts by a plane perpendicular to its principal axis. Find the power of each part in dioptres.

Question

G1 Physics · Accepted Answer

When a symmetric biconvex lens is cut by a plane perpendicular to the principal axis, each part becomes a plano-convex lens. For the original lens: P = 1/f = 1/0.10 = 10 D The curvature contribution is halved, so each half has half the original power: P₁ = 10/2 = 5 D Final answer: 5.