Question

Which one of the following spherical lenses does not exhibit dispersion? The radii of curvature of the surfaces of the lenses are as given in the diagrams

• A.
• B.
• C.
• D.

Answer 1

Answer: (C)

Answer 2

$\frac{1}{f}=(\mu-1)\Bigg(\frac{1}{R_1}-\frac{1}{R_2}\Bigg)$ For no dispersion d\Bigg\\{\frac{1}{f}\Bigg\\}=0 or \hspace15mm R_1=R_2