A convex lens of power +4 D is brought in contact with a

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 -Anyway coming to your question the requirement of +- 4D for a job means that the eyesht of an applicant should not exceed these values that is +4D and -4D and in other