Three concentric spherical shells have radii a, b and c(a<b<c) and have surface charge densities σ,-σ and σ respectively. If V_A, V_B and V_C denote…

Three concentric spherical shells have radii $\displaystyle a, b$ and $\displaystyle c(a<b<c)$ and have surface charge densities $\displaystyle \sigma,-\sigma$ and $\displaystyle \sigma$ respectively. If $\displaystyle \mathrm{V}_{\mathrm{A}}, \mathrm{V}_{\mathrm{B}}$ and $\displaystyle \mathrm{V}_{\mathrm{C}}$ denote the potentials of the three shells, then, for $\displaystyle c=a+b$, we have :