If five identical charged particles of charge ' $q$ ' each are kept at vertices of regular hexagon, then force acting on a charge '$- q$ ' kept at centre of hexagon is (Here, $r$ is distance of vertex from, centre of hexagon)

In the given figure, if $Q_1$ and $Q_2$ are positive, where could a negative charge be placed to have vertically upward net force on it?

In the given figure, if the vertical distance from point $E$ to $B$ is the same as the horizontal from $D$

In the given figure, the vertical distance from point $E$ to $B$ is the same as the horizontal distance from $E$ to either charge and the electric field at $B$ due to either charge has magnitude $1.0\times {10}^6$. If $Q_1$ is negative and $Q_2$ is positive, what is the direction of the net electric field at $B$$?$

In the following figure, the electric field on $y-$axis will be maximum at $y=$

Figure shows charge beads with charges as shown in figure. The charges are placed upon the corners of a square. Rank the magnitude of electric field at the centre in decreasing order.