What will be the magnitude of electric field at point $O$ as shown in figure ? Each side of the figure is $I$ and perpendicular to each other.
$\frac{q}{4 \pi \varepsilon_{0}(l)^{2}}$
$\frac{1}{4 \pi \varepsilon_{0}} \frac{q}{(2l^{2})}(2 \sqrt{2}-1)$
$\frac{1}{4 \pi \varepsilon_{0}} \frac{q}{l^{2}}$
$\frac{1}{4 \pi \varepsilon_{0}} \frac{2 {q}}{2l^{2}}(\sqrt{2})$
Whose result the whole electrostatic is ?
A hollow sphere of charge does not produce an electric field at any
Four point charges $-q, +q, +q$ and $-q$ are placed on $y$ axis at $y = -2d$, $y = -d, y = +d$ and $y = +2d$, respectively. The magnitude of the electric field $E$ at a point on the $x -$ axis at $x = D$, with $D > > d$, will vary as
What is the magnitude of a point charge due to which the electric field $30\,cm$ away has the magnitude $2\,newton/coulomb$ $[1/4\pi {\varepsilon _0} = 9 \times {10^9}\,N{m^2}/{C^2}]$
Two point charges $q_1$ and $q_2 (=q_1/2)$ are placed at points $A(0, 1)$ and $B(1, 0)$ as shown in the figure. The electric field vector at point $P(1, 1)$ makes an angle $\theta $ with the $x-$ axis, then the angle $\theta$ is