Question

Choose the correct answer from the alternatives given.
A plane electromagnetic wave of frequency 50 MHz travels in free space along the x - direction. At a particular point in space and time, $\stackrel{-}{E}=6.3\stackrel{\wedge }{j}V{m}^{-1}$. At this point $B$ is equal to:

• A. $8.33\times {10}^{-8}\stackrel{\wedge }{k}T$
• B. $18.9\times {10}^{-8}\stackrel{\wedge }{k}T$
• C. $4.1\times {10}^{-8}\stackrel{\wedge }{k}T$
• D. $2.1\times {10}^{-8}\stackrel{\wedge }{k}T$

Answer 1

The correct option is D $2.1\times {10}^{-8}\stackrel{\wedge }{k}T$

At any point

$\frac{E}{B}=C\Rightarrow \frac{6.3}{B}=3\times {10}^8\hat{k}=2.1\times {10}^{-8}\hat{k}$