A plane electromagnetic wave of frequency 50 MHz travels in free space along the x-direction. At a particular point in space and time $\vec E=9.3\hat j\, V m^{-1}$. What is $\vec B$ at this point?

$(3.1 × 10^{-8}\hat k) T$ $(3.1 × 10^{-8}\hat i) T$ $(3.1 × 10^{8}\hat k) T$ $(3.1 × 10^{-8}\hat j) T$

$(3.1 × 10^{-8}\hat k) T$

The correct answer is Option (1) → $(3.1 × 10^{-8}\hat k) T$