If on the concentric hollow spheres of radii $r$ and $R( > r)$ the charge $Q$ is distributed such that their surface densities are same then the potential at their common centre is
$\frac{{Q({R^2} + {r^2})}}{{4\pi {\varepsilon _0}(R + r)}}$
$\frac{{QR}}{{R + r}}$
Zero
$\frac{{Q(R + r)}}{{4\pi {\varepsilon _0}({R^2} + {r^2})}}$
Two condensers $C_1$ and $C_2$ in a circuit are joined as shown in figure. The potential of point $A$ is $V_1$ and that of $B$ is $V_2$. The potential of point $D$ will be
The electric potential $V$ at any point $O$ ($x, y, z$ all in metre) in space is given by $V=4x^2\, volt$. The electric field at the point $(1\,m, 0, 2\,m)$ in $volt/meter$ is
Charge of $2Q$ and $-Q$ are placed on two plates of a parallel plate capacitor if capacitance of capacitor is $C$ find potential difference between the plates
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Electric flux through surface $s_1$ :-