Optics 3 Question 19
19. 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
$(2002,2 M)$
(a)
(b)
(c)
(d)
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Answer:
Correct Answer: 19. (c)
Solution:
- $\frac{1}{f}=(\mu-1) \Big(\frac{1}{R _1}-\frac{1}{R _2}\Big)$
For no dispersion, $d \Big(\frac{1}{f}\Big)=0$
or
$$ R _1=R _2 $$
