Two concentric conducting thin spherical shells $A$ and $B$ having radii $r_A$ and $r_B\left(r_B>r_A\right)$ are charged to $Q_A$ and $-Q_B\left(\left|Q_B\right|>\left|Q_A\right|\right)$. The electrical field along a line, (passing through the centre is)

$\left|Q_B\right|>\left|Q_A\right|$ (given). Inside the shell $B$, the potential is a constant and negative. But $V_A$ inside $r_A$ is positive and greater than that of $B$ because $r_A < r_B$. Upto $r_B$, one as hence positive potential. Beyond $r_A, V_A \propto(1 / r)$, this is $>V_B$, one gets the course $\propto 1 / r$. At $B$, the negative potential is more therefore the potential line is still negative. (c) explains all these factors. Note: However the question asked is the field and the diagrams given are for the potential. This is an error. $$ \begin{aligned} & \text { Resistance }=\frac{\text { potential difference }}{\text { current }} \\ & =\frac{\mathrm{ML}^2 \mathrm{~T}^{-3} \mathrm{~A}^{-1}}{\mathrm{~A}}=\left[\mathrm{ML}^2 \mathrm{~T}^{-3} \mathrm{~A}^{-2}\right] \text {. } \\ & \end{aligned} $$