The Brewster angle for air to glass transition of light is
(Refractive index of glass = \( 1.5 \)
Brewster's angle \( \theta_B \) is given by \( \tan \theta_B = n \). For air-to-glass transition, where \( n = 1.5 \), we use \( \theta_B = \tan^{-1} (1.5) \).
\( \cos^{-1} \left(\frac{2}{3}\right) \)
Step 1: Understanding Brewster's Law
Brewster's angle \( \theta_B \) is the angle of incidence at which light with a particular polarization is perfectly transmitted through a transparent dielectric surface without any reflection. It is given by: \[ \tan \theta_B = n \] where \( n \) is the refractive index of the second medium (glass) concerning the first medium (air).
Step 2: Apply the given values
Given \( n = 1.5 \), the Brewster angle is: \[ \theta_B = \tan^{-1} (n) \] \[ \theta_B = \tan^{-1} \left(\frac{3}{2}\right) \]
Step 3: Identify the correct option
From the given answer choices, the correct expression is: \[ \tan^{-1} \left(\frac{3}{2}\right) \] Thus, the correct answer is Option (3).

A transparent block A having refractive index $ \mu_2 = 1.25 $ is surrounded by another medium of refractive index $ \mu_1 = 1.0 $ as shown in figure. A light ray is incident on the flat face of the block with incident angle $ \theta $ as shown in figure. What is the maximum value of $ \theta $ for which light suffers total internal reflection at the top surface of the block ?