There is small air bubble inside a glass sphere `(mu=1.5)` of radius 10 cm. The bubble is 4.0 cm below the surface and is viewed normally from the outside figure. Find the apparent depth of the bubble

Explanation

The observer sees the image formed due to refraction at the spherical surface when the light formt he bubble goes from the glass to the air.
Here, `u=-4.0cm, R=-10cm, mu=1.5` and `mu_(2)=1`.
`(1)/(v)+(-1.5)/(-4.0cm)=(1-1.5)/(-10cm)`
`(1)/(v)=(0.5)/(10cm)-(1.5)/(4.0cm)`
`v=-3.0cm` .
Thus, the bublle will appear `3.0 cm` below the surface.