A plane electromagnetic wave, has frequency of $2.0 \times 10^{10} H z$ and its energy density is $1.02 \times 10^{- 8} J / m^{3}$ in vacuum. The amplitude of the magnetic field of the wave is close to
$(\frac{1}{4 π ε_{0}} = 9 \times 10^{9} \frac{N m^{2}}{C^{2}} a n d s p e e d o f l i g h t = 3 \times 10^{8} m s^{- 1})$ :

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Infinity Learn · Accepted Answer

Energy density $$=B022$$μ$$0=B02$$∈$$02$$μ$$0$$∈$$0=B02C2$$∈$$02$$        $$asC2=1$$μ$$0$$∈$$0$$⇒$$B0=1C2Energy$$ density∈$$0$$​⇒$$B0=13$$×$$1082$$×$$1.02$$×$$10$$−$$84$$π∈$$04$$π$$=13$$×$$1082$$×$$1.02$$×$$10$$−$$8$$×$$9$$×$$109$$×$$4$$π$$=160.11$$×$$10$$−$$9T$$

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A plane electromagnetic wave, has frequency of 2.0×1010 Hz and its energy density is 1.02×10−8J/m3 in vacuum. The amplitude of the magnetic field of the wave is close to 14πε0=9×109Nm2C2and speed of light =3×108 ms−1:

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