The electric field in an electromagnetic wave is given as E → = 20 sin ω t - x c j → N C - 1 , where ω and c are angular frequency and velocity of electromagnetic wave respectively. The energy contain

Question

The electric field in an electromagnetic wave is given as
$\vec{E} = 20 \sin ω (t - \frac{x}{c}) \vec{j} N C^{- 1}$ , where $ω$ and $c$ are angular frequency and velocity of electromagnetic wave respectively. The energy contained in a volume of $5 \times 10^{- 4} m^{3}$ will be
(Given $ε_{0} = 8.85 \times 10^{- 12} C^{2} N^{- 1} m^{- 2}$ )

TestHub · Accepted Answer

Given that, E → = 20 sin ω t - x c j → N C - 1 The average energy density of an electromagnetic wave is 1 2 ε 0 E 2 0 . The total energy stored is E total = 1 2 ε 0 E 0 2 × v o l u m e ⇒ E t o t a l = 1 2 × 8 . 85 × 10 - 12 × ( 20 ) 2 × 5 × 10 - 4 = 8 . 85 × 10 - 13 J

Physics - EM Waves Question with Solution | TestHub

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