Question

Of a convex lens, a plano-convex lens and a concave lens of equal focal lengths, an image with minimum spherical aberration can be produced by :

• A. Any lens
• B. Convex lens
• C. Plano - convex lens
• D. Concave lens

Answer 1

Answer: (C)

Plano - convex lens

The spherical aberration is less if the total deviation of the rays is distributed over the two surfaces of the lens. And in a plano-convex lens, total deviation is distributed at both the surfaces, so, it produces image with minimum spherical aberration.