Three concentric metallic shells $A, B$ and $C$ of radii $a, b$ and $c (a < b < c)$ have surface charge densities $\sigma ,\, - \sigma $ and $\sigma $ respectively. then ${V_A}$ and ${V_B}$
$\frac{\sigma }{{{\varepsilon _0}}}(a - b +c),\,\frac{\sigma }{{{\varepsilon _0}}}\left( {\frac{{{a^2}}}{b} - b + c} \right)$
$(a - b - c),\,\frac{{{a^2}}}{c}$
$\frac{{{\varepsilon _0}}}{\sigma }(a - b - c),\,\frac{{{\varepsilon _0}}}{\sigma }\left( {\frac{{{a^2}}}{c} - b + c} \right)$
$\frac{\sigma }{{{\varepsilon _0}}}\left( {\frac{{{a^2}}}{c} - \frac{{{b^2}}}{c} + c} \right)$ ,$\frac{\sigma }{{{\varepsilon _0}}}(a - b + c)$
Derive an expression for the electric potential in a electric field of positive point charge at distance $\mathrm{r}$.
Variation in electric potential is maximum if one goes
Charges of $ + \frac{{10}}{3} \times {10^{ - 9}}C$ are placed at each of the four corners of a square of side $8\,cm$. The potential at the intersection of the diagonals is
A spherical conductor of radius $2\,m$ is charged to a potential of $120\,V.$ It is now placed inside another hollow spherical conductor of radius $6\,m.$ Calculate the potential to which the bigger sphere would be raised......$V$
Charges are placed on the vertices of a square as shown. Let $E$ be the electric field and $V$ the potential at the centre. If the charges on $A$ and $B$ are interchanged with those on $D$ and $C$ respectively, then