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Question
Why upper surface of water contained in a beaker and above eye level appears silvery?
Solution
Critical angle for water is 49°. The rays of light entering the water from below, suffer refraction. If these rays strike the water-air surface at an angle which is greater than 48°, they get totally internally reflected. These rays on emerging out of the water, appear to come from the upper surface of the water, which in turn appears silvery.
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