Question

20.17N.
Explain with a suitable diagram how
refractive index can he calculated from
real depth and apparent depth?​

Answer 1

Answer:

refractive index is equal to speed of object in light divided speed of object in the medium

Answer 2

Explanation:

We can prove this if you dont understand the formula.

Suppose MM is a point object at an actual depth MAMA below the free surface of water XYXY in a tank.

A ray of light incident on XYXY normally along MAMA passes straight along MAA′MAA′.Another ray of light from MM incident at ∠i∠i on XYXY,along MBMB gets deviated away from normal and is refracted at ∠r∠r along BCBC.If we produce BCBC we will find that it meets OAOA at LL.Therefore LL is virtual image of MM which appears when we see from CC.Now the apparent depth is ALAL.

∠AMB=∠MBN′∠AMB=∠MBN′

∠ALB=∠NBC