First slide

Huygen's Wave Theory

Question

The wavefront of a light beam is given by the equation x + 2y + 3z = c (where c is arbitrary constant), then the angle made by the direction of light with the y-axis is

Moderate

A

$\cos^{- 1} \frac{1}{\sqrt{14}}$
B

$\sin^{- 1} \frac{2}{\sqrt{14}}$
C

$\cos^{- 1} \frac{2}{\sqrt{14}}$
D

$\sin^{- 1} \frac{3}{\sqrt{14}}$

Solution

The wavefront equation must be $a x + b y + c z = 1$ where $a^{2} + b^{2} + c^{2} = 1$ . Applying this we get $1^{2} + 2^{2} + 3^{2} = c^{2} \Rightarrow c = \sqrt{14}$ . So angle with the Y axis is $C o s^{- 1} (\frac{2}{\sqrt{14}})$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App