Angle between equipotential surface and lines of force is.......$^o$
$0$
$180$
$90$
$45$
Two charges $q_1$ and $q_2$ are placed $30\,cm$ apart, as shown in the figure. A third charge $q_3$ is moved along the arc of a circle of radius $40\,cm$ from $C$ to $D$. The change in the potential energy of the $\frac{{{q_3}}}{{4\pi \,{ \in _0}}}k$ , where $k$ is
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.
Two point charges $+8q$ and $-2q$ are located at $x = 0$ and $x = L$ respectively. The location of a point on the $x-$ axis at which the net electric field due to these two point charges is zero is
Electric potential at any point is : $V = -5x + 3y + \sqrt {15} z$ ; then the magnitude of electric field is :-
In a parallel plate air capacitor, a cathode beam comprising $n = 10^6$ electrons is emitted with a velocity $v_0 = 10^8\ m/s$ into the space between the plates. The potential difference between the plate is $\phi = 400\ V$ ,the seperation between the plates is $d = 2\ cm$ and the area of each plate is $l^2 = 100\ cm^2$ . The deflection of the electron beam, is ........... $mm$