A charge $+q$ is fixed at each of the points $x = x_0,\,x = 3x_0,\,x = 5x_0$, .... upto $\infty $ on $X-$  axis and charge $-q$ is fixed on each of the points $x = 2x_0,\,x = 4x_0,\,x = 6x_0$, .... upto $\infty $ . Here $x_0$ is a positive constant. Take the potential at a point due to a charge $Q$ at a distance $r$ from it to be $\frac{Q}{{4\pi {\varepsilon _0}r}}$. Then the potential at the origin due to above system of charges will be

Do free electrons travel to region of higher potential or lower potential ?

Electric charges of $+10\,\mu\, C, +5\,\mu\, C, -3\,\mu\, C$ and $+8\,\mu\, C$ are placed at the corners of a square of side$\sqrt 2\,m$ . The potential at the centre of the square is

Uniform electric field of magnitude $ 100$ $V/m$ in space is directed along the line $y$ $=$ $3$ $+$ $x$. Find .........$V$ the potential difference between point $A (3, 1)$ $ \&$ $ B$ $ (1, 3)$

A thin spherical shell is charged by some source. The potential difference between the two points $C$ and $P$ (in $V$) shown in the figure is:

(Take $\frac{1}{4 \pi \varepsilon_0}=9 \times 10^9$ $SI$ units)

Electric charges of $ + 10\,\mu C,\; + 5\,\mu C,\; - 3\,\mu C$ and $ + 8\,\mu C$ are placed at the corners of a square of side $\sqrt 2 \,m$. the potential at the centre of the square is