The electric field in an electromagnetic wave is given by \(\vec{E}=\hat{i} 40 \cos \omega \left(t - \frac{z}{c}\right)NC^{-1}\). The magnetic field induction of this wave is (in SI unit):
1
\(\vec{B}=\hat{i} \frac{40}{c}\cos \omega \left(t - \frac{z}{c}\right)\)
2
\(\vec{B}=\hat{j} 40 \cos \omega \left(t - \frac{z}{c}\right)\)
3
\(\vec{B}=\hat{k} \frac{40}{c} \cos \omega \left(t - \frac{z}{c}\right)\)
4
\(\vec{B}=\hat{j} \frac{40}{c}\cos \omega \left(t - \frac{z}{c}\right)\)