Energy of an electromagnetic wave contained in a small volume oscillates with

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8.Electromagnetic waves

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The energy of an electromagnetic wave contained in a small volume oscillates with

A

zero frequency

B

half the frequency of the wave

C

double the frequency of the wave

D

the frequency of the wave

(JEE MAIN-2023)

Solution

$E=E_0 \sin (\omega t-k x)$

Energy density $\left(\frac{d u}{d v}\right)=\varepsilon_0 E_0^2 \sin ^2(\omega t-k x)$

$\frac{\varepsilon_0 E _0^2}{2}[1-\cos (2 \omega t -2 kx )]$

Standard 12

Physics

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