Question

Four charges of $6\mu \text{C},2\mu \text{C},-12\mu \text{C}\text{and}4\mu \text{C}$ are placed at the corners of a square of side $1\text{m}$. The square is in xy-plane and its center at its origin. Electric potential due to these charges is zero everywhere on the line

• A. $x=y,z=0$
• B. $x=0=z$
• C. $x=0=y$
• D. $x=z,y=0$

Answer 1

The correct option is C $x=0=y$

As potential is a scalar quantity and the net potential is given by,

$V_{net}=K{\sum }_{i=1}^n\left(\frac{Q}{r}\right)$

$\because Z$ -axis is $\perp$ to the $xy$ plane, thus $r$ is same for all four charges,

So, $V_{net}=\frac{k}{r}[6+2+4-12]$

$V_{net}=0$



$\therefore$ The electric potential due to given charges is zero everywhere on the line $x=0=y$