An electromagnetic wave is propagating in vacuum along $-\hat{\mathrm{j}}$ direction. The magnetic field of the wave is given by $\overrightarrow{B}=\left(2\times {10}^{-8}\right)\cos \left[\pi \times {10}^{15}\left(t+\frac{y}{c}\right)\right] \hat{\mathrm{k}} \mathrm{T}$. The electric field $\overrightarrow{E}$ of this wave is ($c=$ speed of light)

• A

  $\overrightarrow{E}=\left(4\right)\cos \left[\pi \times {10}^{15}\left(t+\frac{y}{c}\right)\right] \hat{\mathrm{j}} \mathrm{V} {\mathrm{m}}^{-1}$
• Correct answer
  B

  $\overrightarrow{E}=\left(6\right)\cos \left[\pi \times {10}^{15}\left(t+\frac{y}{c}\right)\right] \hat{\mathrm{i}} \mathrm{V} {\mathrm{m}}^{-1}$
• C

  $\overrightarrow{E}=\left(6\right)\cos \left[\pi \times {10}^{15}\left(t-\frac{y}{c}\right)\right] \hat{\mathrm{j}} \mathrm{V} {\mathrm{m}}^{-1}$
• D

  $\overrightarrow{E}=\left(4\right)\cos \left[\pi \times {10}^{15}\left(t-\frac{y}{c}\right)\right] \hat{\mathrm{i}} \mathrm{V} {\mathrm{m}}^{-1}$

Hence, the correct answer is option: 'B'.