A point source of light is placed 4 cm 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

A point source of light is placed 4 cm below the surface of water of r

1.	A point source of light is placed 4 cm 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
Answer» infnite 6 cm 4 cm 3 cm Solution :`r=(h)/(sqrt(mu^(2)-1))=(4)/(sqrt(((5)/3)^(2))-1)=3M` , Diameter = 2r = 6M

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A point source of light is placed 4 cm 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

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