Oscillating magnetic field in a plane electromagnetic wave is given by B _{ y }=5 × 10^{-6} sin 100

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8.Electromagnetic waves

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The oscillating magnetic field in a plane electromagnetic wave is given by $B _{ y }=5 \times 10^{-6} \sin$ $1000\,\pi\left(5 x -4 \times 10^{8} t \right) T$. The amplitude of electric field will be.

A

$15 \times 10^{2} \,Vm ^{-1}$

B

$5 \times 10^{-6} \,Vm ^{-1}$

C

$16 \times 10^{12} \,Vm ^{-1}$

D

$4 \times 10^{2} \,Vm ^{-1}$

(JEE MAIN-2022)

Solution

$B _{0}=5 \times 10^{-6}$

$v =$ Speed of wave $=\frac{4 \times 10^{8}}{5}=8 \times 10^{7}\left[\therefore v =\frac{ w }{ k }\right]$

$E _{0}= vB B _{0}=40 \times 10^{1}$

$=4 \times 10^{2} V / m$

Standard 12

Physics

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