A plane electromagnetic wave, has frequency of 2.0 × 10^10 Hz and its energy density is 1.02 × 10^-8 J / m^3 in vacuum. The amplitude of the magnetic…

A plane electromagnetic wave, has frequency of $\displaystyle 2.0 \times 10^{10} \mathrm{~Hz}$ and its energy density is $\displaystyle 1.02 \times 10^{-8} \mathrm{~J} / \mathrm{m}^3$ in vacuum. The amplitude of the magnetic field of the wave is close to $\displaystyle \left(\frac{1}{4 \pi \epsilon_0}=9 \times 10^9 \frac{\mathrm{Nm}^2}{\mathrm{C}^2}\right.$ and speed of light $\displaystyle =3 \times 10^8 \mathrm{~ms}^{-1}$ ):