Question

The velocity of light in air is 3×10⁸ m s^-1 and that in water is 2.2×10⁸ m s^-1. The polarizing angle of incidence is:

• A. 45⁰
• B. 50⁰
• C. 53.74⁰
• D. 63⁰

Answer 1

Answer: (C)

53.74⁰

Answer 2

The refractive index of water

$\mu = \frac{speedoflightinair}{speedoflightinwater} = \frac{3 \times 10^{8}}{2.2 \times 10^{8}} = 1.36a$

From Brewsters law,

$\tan i_{p} = \mu = 1.363$

$\therefore i_{p} = \tan^{- 1}(1.36) = 53.74º$