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 source and an observer move away from each other with same velocity of 10 m-1 with respect to the ground. If the observer finds the frequency of sound coming from the source as 1980 Hz, then the actual frequency of the source is (speed of sound in air = 340 ms-1)
Two convex lenses of focal lengths 20 cm and 30 cm are placed in contact with each other co-axially. The focal length of the combination is: