Question

What is the electric potential at the center of a square of side length 2.0 m with alternating + 3C, –2C, +3C, and –2C charges placed at its vertices

Answer 1

Answer

net charge

$q_{net}=3+3-2-2=2C$

Distance of all the charge from center

=$\frac{\sqrt{2^2+2^2}}{2}=1.4m$

So potential at center

$V=\frac{kq}{r^2}=\frac{(9\times10^9) (2) }{1.4^2}=9.2\times10^9V$