When a fish looks up the surface of a perfectly smooth lake, the surface appears dark except inside a circular area directly above it. Calculate the angle that this illuminated region subtends. Given `mu` of water `= 1.333`.

When a fish looks up the surface of a perfectly smooth lake, the surfa

1.	When a fish looks up the surface of a perfectly smooth lake, the surface appears dark except inside a circular area directly above it. Calculate the angle that this illuminated region subtends. Given `mu` of water `= 1.333`.
Answer» Correct Answer - `97.2^(@)` Here, `mu = 1.333, 2 theta = ?` `sin C = (1)/(mu) = (1)/(1.333) = 0.75` `C = sin^(-1)(0.75) = 48.6^(@)`. Angle which illuminated region subtends `= 2 theta = 2 C = 2 xx 48.6^(@) = 97.2^(@)`

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When a fish looks up the surface of a perfectly smooth lake, the surface appears dark except inside a circular area directly above it. Calculate the angle that this illuminated region subtends. Given `mu` of water `= 1.333`.

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