Electrostatics

Two electric charges $+2 \mu \mathrm{C}$ and $-4 \mu \mathrm{C}$ are separated by a distance 3 m in air. At a point $P$ located on the line joining the two charges and in between them, the electric potential is zero. Then the electric field at a point $P$ (in $\mathrm{NC}^{-1}$ ) is