Power (P) of a lens is given by reciprocal of focal length (f) of

power 4dThe focal length of a lens with a power of +4D is 25 cm. Show More | Share Save. Class 12 PHYSICS GEOMETRICAL OPTICS. Topper's Solved these Questions. OPTICS BOOK -With our 4DX PowerPoint template, you'll receive all the integral information about the four discips and a wide selection of templates to introduce the 4DX in your company. Present