Question

A point charge of 0.009 $\mu C$ is placed at the origin. Calculate the intensity of electric field due to this point charge at point ($\sqrt{2},\sqrt{7},0$) m.

Answer 1

Distance of point from the origin, $d=\sqrt{2+7}=3m$

Magnitude of electric field $E=\frac{KQ}{r^2}$

Or $E=\frac{9\times {10}^9\times 0.009\times {10}^{-6}}{3^2}=9N/C$