Question 102 of 311

What will be the magnitude of the electric field at point $O$ as shown in the figure? Each side of the figure is $l$ and perpendicular to the other?

A$\dfrac{1}{4\pi {\epsilon }_{0}}\dfrac{q}{{l}^{2}}$B$\dfrac{1}{4\pi {\epsilon }_{0}}\dfrac{q}{\left(2{l}^{2}\right)}(2\sqrt{2}-1)$C$\dfrac{q}{4\pi {\epsilon }_{0}(2l{)}^{2}}$D$\dfrac{1}{4\pi {\epsilon }_{0}}\dfrac{2q}{2{l}^{2}}(\sqrt{2})$

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Answer: (B) $\dfrac{1}{4\pi {\epsilon }_{0}}\dfrac{q}{\left(2{l}^{2}\right)}(2\sqrt{2}-1)$

${E}_{1}=\dfrac{kq}{{l}^{2}}={E}_{2}$
${E}_{3}=\dfrac{kq}{(\sqrt{2}\ell l}=\dfrac{kq}{2{l}^{2}}$
$E=\dfrac{\sqrt{2}kq}{{l}^{2}}-\dfrac{kq}{2{l}^{2}}=\dfrac{kq}{2{l}^{2}}(2\sqrt{2}-1)$

JEE Main Physics practice question on Electrostatics (Electric Field and Electric Field Lines), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.