A) \[\frac{f}{2}and\frac{I}{2}\]
B) \[f\,and\frac{I}{4}\]
C) \[\frac{3f}{4}\,and\frac{I}{2}\]
D) \[f\,and\frac{3I}{4}\]
Correct Answer: D
Solution :
If the area of lens of diameter \[d\] is\[A\], then the area of the central opaque part is\[\frac{A}{4}\], so area of the remaining transparent part is\[\frac{3A}{4}\]. So, the amount of light entering the glass is three-fourth of initial. Amount of light energy means, intensity. Focal length of a lens depends only on\[\mu ,\,\,{{R}_{1}},\,\,{{R}_{2}}\]. Since these are constant, focal length will remain same.You need to login to perform this action.
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