Q26E - University Physics with Modern Physics

Question

(a) At what angle above the horizontal is the sun if sunlight reflected from the surface of a calm lake is completely polarized? (b) What is the plane of the electric-field vector in the reflected light?

Step-by-Step Solution

Answer

1. The angle above the horizontal is
2. The plane is perpendicular to the incident light plane, which is the horizontal plane.

Step 1: Brewster’s law

Brewster’s law for polarising angle;

Here,

Step 2: Angle above the horizontal

Medium${\mathrm{n}}_1$is air

Medium${\mathrm{n}}_2$for water RI is 1.33

       (a) So, the angle is;

 

Step 3: Plane of the electric-field vector in the reflected light

  (b) Hence, the plane is perpendicular to the incident light plane, which is the horizontal plane.