A plane electromagnetic wave propagating in $x$ -direction is described by
$E_{y} = (200 V m^{- 1}) \sin [1.5 \times 10^{7} t - 0.05 x];$ The intensity of the wave is :
(Use $ϵ_{0} = 8.85 \times 10^{- 12} C^{2} N^{- 1} m^{- 2}$ )

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TestHub · Accepted Answer

The magnitude of the electric field component of the electromagnetic wave is given by

$E_{0} = 200 V m^{- 1}$

The formula to calculate the intensity of the electromagnetic wave is given by

$I = \frac{1}{2} ε_{0} c E_{0}^{2} . . . (1)$

From equation (1), it follows that

$\begin{array}{rcl} I & = & \frac{1}{2} \times 8.85 \times 10^{- 12} \times 3 \times 10^{8} \times {(200)}^{2} W m^{- 2} \\ = & 53.1 W m^{- 2} \end{array}$

Physics - EM Waves Question with Solution | TestHub

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