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Question:

A hemispherical glass body of radius 10 cm and refractive index 1.5 is silvered on its curved surface. A small air bubble is 6 cm below the flat surface inside it along the axis. The position of the image of the air bubble made by the mirror is seen:

20 cmbelow flat surface

14 cmbelow flat surface

16 cmbelow flat surface

30 cmbelow flat surface

Solution:

Mirror formula gives : 1/v + 1/u = 1/f ⇒ 1/v + 1/-8 = 1/-10 ⇒ v = 20cm
Image will form 10 + 20 = 30cm below the flat surface.
Now, Apparent Depth/Real Depth = Refractive Index of Air/Refractive Index of Medium