Answer
$I=1.2\times 10^6W/m^2$
Work Step by Step
The intensity of an electromagnetic wave is equal to the intensity of the Poynting vector, which is $$S=\frac{E_{m}B_{m}}{2\mu_o}$$ Using the relation that $E_{max}=cB_{max}$, the intensity becomes $$S=\frac{cB_m^2}{2\mu_o}$$ Using the value of $B_m=1.0\times 10^{-4}T$ in the equation yields $$S=\frac{(3.00\times 10^8m/s)(1.0\times 10^{-4}T)^2}{2(4\pi \times10^{-7}N/A^2)}=1.2\times 10^6W/m^2$$
