You are here
The refractive indices of three media are given below:
| Medium | Refractive Index |
| A | 1.6 |
| B | 1.8 |
| C | 1.5 |
A ray of light is travelling from A to B and another ray is travelling from B to C.
(a) In which of the two cases the refracted ray bends towards the normal?
Answer:
When the light travels from a medium of low refractive index (rarer medium) to a medium of high refractive index (denser medium), it bends towards the normal.
Since nb>na, the light will bend towards the normal while travelling from medium A to medium B.
(b) In which case does the speed of light increase in the second medium? Give reasons for your answer.
Answer:
The speed of light is given by the formula:
v=c/n where c is the speed of light in air and n is the refractive index.
From this formula, it can be concluded that the speed of light in any medium is inversely
proportional to the refractive index of that medium.
So, the speed of light will increase when it travels from B to C as nc>nb
