Snell's Law (1 Viewer)

[747captain]

Can someone just explain to me what n2 and n1 are?

Thanks.

 

[alcalder]

n₂ and n₁ are the absolute refractive indices of substances 2 and 1 (respectively) calculated when light travels from a vacuum into that substance. These are usually given.

 

[747captain]

thanx alcalder,

so, 4 e.g if it was light from air to water: n2 = 1.33 and n1 = 1.00028
So in that case, you take 1.33/1.00028 = constant?
and if it was light from water to air: n2 = 1.00028 and n1 = 1.33
So in that case, you take 1.00028/1.33 = constant?

Also, my teacher mentioned something about n2 always being larger than n1 or something like that. Don't really get what that means...?

 

[xiao1985]

n2 doesn't have to be always larger than n1... as alcalder said, n1 is the first medium light travelled, whilst n2 is the medium which it enters. however, for total internal reflectance, you need the outer material having a lower reflective index than inner material.

 

[747captain]

ahh. Ok. Got it. Thanks everyone. Really appreciate it.

Good luck with ur studies.

Cheers