At a certain distance from a point charge,the electric field is $500 \ V/m$ and the potential is $3000 \ V$. What is this distance (in $m$)?

Six point charges are kept $60^{\circ}$ apart from each other on the circumference of a circle of radius $R$ as shown in the figure. The net electric field at the centre of the circle is . . . . . . . ($ \epsilon_{0} $ is the permittivity of free space)

Two charges $+5\,\mu C$ and $+10\,\mu C$ are placed $20\,cm$ apart. The net electric field at the midpoint between the two charges is

$A$ uniformly charged semicircular arc of radius $r$ has linear charge density $\lambda$. What is the electric field at its centre? $(\epsilon_0 = \text{permittivity of free space})$

Two charges $9e$ and $3e$ are placed at a distance $r$. At what distance will the electric field be zero?

In the figure shown,the distance from point $A$ to the point where the electric field intensity is zero is .......... $cm$.