Question

An achromatic convergent double of two lenses in contact has a power of +2D. The convex lens has power +5D. What is the ratio of the dispersive powers of the convergent and divergent lenses?

• A. 2 : 5
• B. 3 : 5
• C. 5 : 2
• D. 5 : 3

Answer 1

Answer: (B)