The region y > 0 has a constant electrostatic potential V1 and y < 0 has a constant electrostatic potential V2 ≠ V1. A charged particle with momentum \(\overrightarrow{p_1}\) is incident at an angle θ1 on the interface of the two regions (see figure below).
If the particle has momentum \(\overrightarrow{p_2}\) in the region y < 0, then the angle θ2 is given by
1
\(\cos ^{-1}\left(\frac{\mathrm{p}_2}{\mathrm{p}_1} \cos \theta_1\right)\)
2
\(\cos ^{-1}\left(\frac{\mathrm{p}_1}{\mathrm{p}_2} \cos \theta_1\right)\)
3
\(\sin ^{-1}\left(\frac{\mathrm{p}_2}{\mathrm{p}_1} \sin \theta_1\right)\)
4
\(\sin ^{-1}\left(\frac{\mathrm{p}_1}{\mathrm{p}_2} \sin \theta_1\right)\)