In a plane EM wave,the electric field oscilla | vedclass

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(A) The total average energy density $u_{avg}$ of an electromagnetic wave is the sum of the average electric energy density $u_E$ and the average magn

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$1.106 	imes 10^{-8} \,Jm^{-3}$

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(A) The total average energy density $u_{avg}$ of an electromagnetic wave is the sum of the average electric energy density $u_E$ and the average magnetic energy density $u_B$.In an $EM$ wave,$u_E = u_B$,so $u_{avg} = u_E + u_B = 2u_E$.The average electric energy density is given by $u_E = \frac{1}{4} \epsilon_0 E_0^2$,where $E_0$ is the amplitude of the electric field.Thus,the total average energy density is $u_{avg} = 2 	imes (\frac{1}{4} \epsilon_0 E_0^2) = \frac{1}{2} \epsilon_0 E_0^2$.Given $\epsilon_0 = 8.85 	imes 10^{-12} \,C^2/Nm^2$ and $E_0 = 50 \,Vm^{-1}$.Substituting the values: $u_{avg} = \frac{1}{2} 	imes 8.85 	imes 10^{-12} 	imes (50)^2$.$u_{avg} = 0.5 	imes 8.85 	imes 10^{-12} 	imes 2500$.$u_{avg} = 1.10625 	imes 10^{-8} \,Jm^{-3}$.

In a plane $EM$ wave,the electric field oscillates sinusoidally at a frequency of $5 \times 10^{10} \,Hz$ and an amplitude of $50 \,Vm^{-1}$. The total average energy density of the electromagnetic field of the wave is :
[Use $\varepsilon_0 = 8.85 \times 10^{-12} \,C^2 / Nm^2$ ]

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In a plane $EM$ wave,the electric field oscillates sinusoidally at a frequency of $5 \times 10^{10} \,Hz$ and an amplitude of $50 \,Vm^{-1}$. The total average energy density of the electromagnetic field of the wave is :[Use $\varepsilon_0 = 8.85 \times 10^{-12} \,C^2 / Nm^2$ ]