wave-optics Question 35
Question: Q. 4. Which of the following waves can be polarised (i) heat waves, (ii) sound waves. Give reason in support your answer. $\quad$ A&E [OD I, II, III 2013]
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Solution:
Ans. Heat wavés as they are transverse / electromagnetic in nature.
1
[CBSE Marking Scheme 2013]
Short Answer Type Questions-b
(2 marks each)
[A] Q. 1. How is linearly polarised light obtained by the process of scattering of light ? Find the Brewster’s angle for air-glass interface, when the refractive index of glass $=\mathbf{1 . 5}$.
R] [ODH2017]
Ans. When unpolarised light gets scattered by molecules, the scattered light has only one of its two components in it. (Also@ecept diagrammatic representation )
$$ \begin{aligned} & \text { We have, } \ & \therefore \ & \begin{aligned} \mu & =\tan I_{B} \ \tan I_{B} & =1.5 \ I_{B} & =\tan ^{-1} 1.5 \ & =56.3^{\circ} \end{aligned} \ & \therefore \quad I_{B}=\tan ^{-1} 1.5 \end{aligned} $$
[CBSE Marking Scheme 2017]