Question

At what minimum angle in degrees will you get total internal reflection of light when traveling from a medium of index of refraction of 1.63 to a medium with an index of refraction of 1.29. Please show the steps to solve so I understand. Thanks

Answer 1

For a light to undergo total internal reflection the minimum angle of incidence should be such that the angle of refration is = 90⁰

The light travels from medium of index of refraction of 1.63 to a medium with an index of refraction of 1.29.

Let the angle of incidence be i and angle of refraction be r. Then using Snell's law we get;

Sini/Sinr = 1.29/1.63

Now we saw above that r has to be 90⁰

So we have Sini/Sin90⁰ = 0.7914

or Sini = 0.7914 (as Sin90⁰ = 1)

or i = 52.3⁰

So the minimum angle in degrees required for total internal reflection = 52.3⁰

This concludes the answers. Check the answer and let me know if it's correct. If you need anymore clarification I will be happy to oblige...