Ray Optics and Optical Instruments - Result Question 45
47. If and are the focal lengths of a convex lens for violet and red light respectively and and are the focal lengths of concave lens for violet and red light respectively, then we have [1996]
(a)
(b)
(c)
(d)
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Answer:
Correct Answer: 47. (a)
Solution:
- (a)
According to Cauchy relation
Hence, red light having maximum wavelength has maximum focal length.