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8.Electromagnetic waves
medium
A plane electromagnetic wave of frequency $20\,MHz$ propagates in free space along $x$-direction. At a particular space and time, $\overrightarrow{ E }=6.6 \hat{ j } V / m$. What is $\overrightarrow{ B }$ at this point?
A
$-2.2 \times 10^{-8} \hat{ i }\,T$
B
$2.2 \times 10^{-8} \hat{ k }\,T$
C
$-2.2 \times 10^{-8} \hat{ k }\,T$
D
$2.2 \times 10^{-8} \hat{ i }\,T$
(JEE MAIN-2023)
Solution
$\overrightarrow{ E }=6.6 \hat{ j }$
$v=20\,MHz$
$\overrightarrow{ c }=3 \times 10^8 \hat{ i }$
$|\overrightarrow{ B }|=\frac{|\overrightarrow{ E }|}{ c }=2.2 \times 10^{-8}\,T$
$\hat{ E } \times \hat{ B }=\hat{ c }$
$\overrightarrow{ B }=2.2 \times 10^{-8} \hat{ k }\,T$
Standard 12
Physics
