A point source of light is placed 4 m below the surface of water of re – McqOptions

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1.	A point source of light is placed 4 m below the surface of water of refractive index 5 / 3. The minimum diameter of a disc which should be placed over the source on the surface of water to cut?off all light coming out of water is [CBSE PMT 1994; JIPMER 2001, 02]
A.	2 m
B.	6 m
C.	4 m
D.	3 m
Answer» C. 4 m

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