Two Light Waves Are Initially in Phase and Have the Same

Multiple Choice

Two light waves are initially in phase and have the same wavelength, 470 nm. They enter two different media of identical lengths of 2.50 µm. If n₁ = 1.2 and n₂ = 1.5, what is the effective phase difference of the waves when they exit the media?

A) 0 rad
B) 0.6 rad
C) 1.6 rad
D) 3.7 rad
E) 10 rad