A converging set of ray, traveling from water to air, is incident on a plane interface. In the absence of the interface, the rays would have converged to a point O, 60 cm above the interface. However, dur to refraction the rays will bend. At what distance above the interface will the rays actually converge?

Explanation

A ray of light now travels through water, across the interface through air and converges to form an image at I. Here, medium 1 is water and medium 2 is air.
`d_(1)=+60cm, mu_(1)=(4)/(3), mu_(2)=1`
As `(mu_(1))/(d_(1))=(mu_(2))/(d_(2)) ` or `d_(2)=(mu_(2))/(mu_(1))d_(1)`, we get
Thus, the i mage is formed 45 cm above the interface.