Question

What is the relation between the polarizing angle and the refractive index in Brewster’s Law?

• A. $\mu = \sin \theta_p$
• B. $\mu = \cos \theta_p$
• C. $\mu = \tan \theta_p$
• D. $\mu = \cot \theta_p$

Hint:

Remember: Brewster’s Law → $\mu = \tan \theta_p$.

Answer 1

The Correct Option is C

Concept: Brewster’s Law states that at a particular angle of incidence (polarizing angle), the reflected light is completely plane polarized.
Step 1: Brewster’s Law formula.
\[ \mu = \tan \theta_p \] where $\mu$ is the refractive index and $\theta_p$ is the polarizing angle.
Step 2: Physical meaning.
At this angle, the reflected and refracted rays are perpendicular to each other.
Step 3: Evaluating the options.

• $\mu = \sin \theta_p$ $\rightarrow$ Incorrect
• $\mu = \cos \theta_p$ $\rightarrow$ Incorrect
• $\mu = \tan \theta_p$ $\rightarrow$ Correct
• $\mu = \cot \theta_p$ $\rightarrow$ Incorrect

Step 4: Conclusion.
Thus, the relation is $\mu = \tan \theta_p$.