A beam of light travelling along $X$-axis is described by the electric field $E_{y}=900 \sin \omega(\mathrm{t}-x / c)$. The ratio of electric force to magnetic force on a charge $\mathrm{q}$ moving along $Y$-axis with a speed of $3 \times 10^{7} \mathrm{~ms}^{-1}$ will be :
(Given speed of light $=3 \times 10^{8} \mathrm{~ms}^{-1}$)
Solution
<p>Ratio $$ = {{|q\overrightarrow E |} \over {|q\overrightarrow v \times \overrightarrow B |}}$$</p>
<p>$= {E \over {vB}} = {{{v_{wave}}} \over v}$</p>
<p>$\Rightarrow$ Ratio $= {{3 \times {{10}^8}} \over {3 \times {{10}^7}}} = 10$</p>
About this question
Subject: Physics · Chapter: Electromagnetic Waves · Topic: Properties of EM Waves
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