Question
The following table gives the values of refractive indices of a few media:
|
S. No. |
1 |
2 |
3 |
4 |
5 |
|
Medium |
Water |
Crown glass |
Rock salt |
Ruby |
Diamond |
|
Refractive index |
1.33 |
1.52 |
1.54 |
1.71 |
2.42 |
Use this table to give an example of (i) a medium pair so that light speeds up when it goes from one of these media to another. (ii) a medium pair so that light slows down when it goes from one of these media to another.
Solution
When the ray of light travels from a denser (high refractive index) to rarer medium (low refractive index), speed of light ray speeds up. When light ray travels from rarer to denser medium it's speed slows down.
Therefore,
(i) Light speeds up when the ray propagates from crown glass to water.
(ii) Light slows down when it travels from water to diamond.
