1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Angle of Refraction

  1. Apr 18, 2007 #1
    A light beam passes from medium 1 to medium 2 with the latter being a thick slab of material whose index of refraction is n2. Show that the emerging beam is parallel to incident beam.

    Am I correct in assuming that the only way this is possible is to have the incident beam making an angle that is 90 degrees with medium 2? Can someone confirm my thinking.
  2. jcsd
  3. Apr 18, 2007 #2
    If there is only one refraction happening, then yeah. If there are two refractions (if its a slab or something so that the light ray emerges back into medium 1) then it will always be parallel to the incident ray.


    [tex]\mu sinx=k[/tex] where k is a constant, so for sinx1=sinx2, n1=n2. Since n1 & n2 arent the same, the only angle for which the equality holds is 0, which means that the ray falls normally on surface 2.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook