# Q. A plane electromagnetic wave of frequency 50 MHz travels in free space along the positive x-direction. At a particular point in space and time, $\vec{E} = 6.3 \hat{j} V/m$ . The corresponding magnetic field $\vec{B}$ , at that point will be:

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Solution:

## $\left|B\right| = \frac{\left|E\right|}{C} = \frac{6.3}{3 \times10^{8}} =2.1 \times10^{-8} T$ and $\hat{E} \times\hat{B} = \hat{C}$ $\hat{j} \times\hat{B} =\hat{i}$ $\hat{B} = \hat{k}$ $\vec{B} = \left| B\right|\hat{B} = 2.1 \times10^{8} \hat{k} T$

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