Electric Potential Questions

Four electric charges $+q,+q,-q$ and $-q$ are placed at the corners of a square of side $2L$. The electric potential at point $A$, midway between the two charges $+q$ and $+q$, is:

Two concentric conducting thin spherical shells $A$ and $B$ having radii $r_A$ and $r_B$ ($r_B>r_A$) are charged to $Q_A$ and $-Q_B$ ($|Q_B|>|Q_A|$). The electrical field along a line (passing through the centre) is:

The electric potential at a point in free space due to a charge $Q$ coulomb is $Q\times 10^{11}$ volts. The electric field at that point is:

A conducting sphere of radius $R$ is given a charge $Q$. The electric potential and the electric field at the centre of the sphere respectively are:

In a region the potential is represented by $V(x,y,z)=6x-8xy-8y+6yz$, where $V$ is in volts and $x,y,z$ are in meters. The electric force experienced by a charge of $2\text{coulomb}$ situated at point $(1,1,1)$ is:

If potential (in volts) in a region is expressed as $V(x,y,z)=6xy-y+2yz$, the electric field (in N/C) at point $(1,1,0)$ is: