Question

The charge per unit length of the four quadrant of the ring is $2\lambda ,-2\lambda ,\lambda$ and $-\lambda$ respectively. Find the electric field at the centre.

• A. $\frac{2k\lambda }{R}(-\hat{i})$
• B. $\frac{2k\lambda }{R}\left(\hat{i}\right)$
• C. $\frac{2k\lambda }{R}\left(\hat{j}\right)$
• D. $\frac{2k\lambda }{R}(-\hat{j})$

Answer 1

The correct option is A $\frac{2k\lambda }{R}(-\hat{i})$


$E^{net}=\sqrt{2}E$
$=\sqrt{2}\frac{\sqrt{2}K\lambda }{R}=\frac{2K\lambda }{R}$
$E=\frac{-2K\lambda \hat{i}}{R}$