MCQ
A charge $Q$ is distributed over three concentric spherical shell of radii $a, b, c (a < b < c)$ such that their surface charge densities are equal to one another. The total potential at a point at distance $r$ from their common centre, where $r < a$, would be
- A$\frac{Q}{{12\pi \,{ \in _0}}}\frac{{ab + bc + ca}}{{abc}}$
- B$\frac{{Q\,\left( {{a^2} + {b^2} + {c^2}} \right)}}{{4\pi \,{ \in _0}\,\left( {{a^3} + {b^3} + {c^3}} \right)\,}}$
- C$\frac{Q}{{4\pi \,{ \in _0}\,\left( {a + b + c} \right)\,}}$
- ✓$\frac{{Q\,\left( {a + b + c} \right)}}{{4\pi \,{ \in _0}\,\left( {{a^2} + {b^2} + {c^2}} \right)\,\,}}$
