WBJEE · Physics · Ray Optics
The radius of the light circle observed by a fish at a depth of 12 meter is (refractive index of water \(=4 / 3\) )
- A \(36 \sqrt{7}\)
- B \(\frac{36}{\sqrt{7}}\)
- C \(36 \sqrt{5}\)
- D \(4 \sqrt{5}\)
Answer & Solution
Correct Answer
(B) \(\frac{36}{\sqrt{7}}\)
Step-by-step Solution
Detailed explanation
\[ \text { Hints : } r=\frac{h}{\sqrt{\mu^2-1}}=\frac{12}{\sqrt{\frac{16}{9}-1}}=\frac{12 \times 3}{\sqrt{7}}=\frac{36}{\sqrt{7}} \]
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