There is a small air bubble inside a glass sphere (µ = 1.5) of radius 10 cm. The bubble is 4 cm below the surface and is viewed normally from outside. The apparent depth of the bubble is
(1) 3 cm (2) 4 cm (3) cm (4) 6 cm
It should be 4 cm as when seen normally so light will be perpendicular to surface of sphere and hence it will not suffer any deflection. If we would see it from some other angle then it would shift. In case the bubble would have been at the center of sphere then no matter from which position we see it, it'll always be at the center as line joining Center And surface of sphere is always perpendicular so it won't refraction hence there will be no change in depth.