Question

Abc is an equilateral triangle charges +q are placed at each corners the electric intensity at o will be

Answer 1

Answer:

0

Explanation:

As per the diagram (in the attachment) ;

Keeping in mind that $\\\tt E_{1} = E_{2} = E_{3} = \dfrac{1}{4 \pi \epsilon_{\circ}} \dfrac{q}{r^2}$

Net electric field by $\\\tt E_{1}$ and $\\\tt E_{2}$  is given by:

$\\\tt E_{1+2 } =\sqrt{E_{1}^{2} + E_{2}^{2} + 2E_{1} E_{2} \cos\theta} \\\\\tt = \sqrt{2E_{1}^{2} + 2E_{1}^{2}\cos120^{\circ}} \\\\\tt = \sqrt{2E_{1}^{2} + 2E_{1}^{2}(\dfrac{-1}{2}) } \\\\\\\tt = \sqrt{2E_{1}^{2} - E_{1}^{2} } \\= E_{1}$

Now,

Net force between $\\\tt E_{1+2}$ and $\\\tt E_{3}$ are perpendicular to each other they cancel each other out making net electric field 0.