Find the electric field at point $P$ (as shown in figure) on the perpendicular bisector of a uniformly charged thin wire of length $L$ carrying a charge $Q.$ The distance of the point $P$ from the centre of the rod is $a=\frac{\sqrt{3}}{2} L$.
$\frac{\sqrt{3} Q }{4 \pi \varepsilon_{0} L ^{2}}$
$\frac{ Q }{3 \pi \varepsilon_{0} L ^{2}}$
$\frac{Q}{2 \sqrt{3} \pi \varepsilon_{0} L ^{2}}$
$\frac{ Q }{4 \pi \varepsilon_{0} L ^{2}}$
The electric field intensity at a point in vacuum is equal to
Four charges $q, 2q, -4q$ and $2q$ are placed in order at the four corners of a square of side $b$. The net field at the centre of the square is
For the given figure the direction of electric field at $A$ will be
Is electric field scalar or vector ? Why ?
Figures below show regular hexagons, with charges at the vertices. In which of the following cases the electric field at the centre is not zero