Four charges $2C, -3C, -4C$ and $5C$ respectively are placed at all the corners of a square. Which of the following statements is true for the point of intersection of the diagonals ?
Electric field is zero but electric potential is non-zero
Electric field is non-zero but electric potential is zero
Both electric field and electric potential are zero
Neither electric field nor electric potential is zero
Charge is uniformly distributed on the surface of a hollow hemisphere. Let $O$ and $A$ be two points on the base of the hemisphere and $V_0$ and $V_A$ be the electric potentials at $O$ and $A$ respectively. Then,
Ten charges are placed on the circumference of a circle of radius $R$ with constant angular separation between successive charges. Alternate charges $1,3,5,7,9$ have charge $(+q)$ each, while $2,4,6,8,10$ have charge $(-q)$ each. The potential $V$ and the electric field $E$ at the centre of the circle are respectively
(Take $V =0$ at infinity $)$
Two insulated charged spheres of radii $20\,cm$ and $25\,cm$ respectively and having an equal charge $Q$ are connected by a copper wire, then they are separated
$N$ identical spherical drops charged to the same potential $V$ are combined to form a big drop. The potential of the new drop will be
A thin spherical conducting shell of radius $R$ has a charge $q$. Another charge $Q$ is placed at the centre of the shell. The electrostatic potential at a point $p$ at distance $\frac{R}{2}$ from the centre of the shell is