A charge Q is distributed over three concentric spherical shells 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

\(\frac{Q}{{4\pi {\varepsilon _0}\left( {{\rm{a}} + {\rm{b}} + {\rm{c}}} \right)}}\)

\(\frac{{Q\left( {{a^2} + {b^2} + {c^2}} \right)}}{{4\pi {\varepsilon _0}\left( {{a^3} + {b^3} + {c^3}} \right)}}\)

\(\frac{{Q\left( {a + b + c} \right)}}{{4\pi {\varepsilon _0}\left( {{a^2} + {b^2} + {c^2}} \right)}}\)

\(\frac{Q}{{12\pi {\varepsilon _0}}}\frac{{ab + bc + ca}}{{abc}}\)

A charge Q is distributed over three concentric spherical shells of ra

1.	A charge Q is distributed over three concentric spherical shells 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.	\(\frac{{Q\left( {{a^2} + {b^2} + {c^2}} \right)}}{{4\pi {\varepsilon _0}\left( {{a^3} + {b^3} + {c^3}} \right)}}\)
B.	\(\frac{{Q\left( {a + b + c} \right)}}{{4\pi {\varepsilon _0}\left( {{a^2} + {b^2} + {c^2}} \right)}}\)
C.	\(\frac{Q}{{4\pi {\varepsilon _0}\left( {{\rm{a}} + {\rm{b}} + {\rm{c}}} \right)}}\)
D.	\(\frac{Q}{{12\pi {\varepsilon _0}}}\frac{{ab + bc + ca}}{{abc}}\)
Answer» C. \(\frac{Q}{{4\pi {\varepsilon _0}\left( {{\rm{a}} + {\rm{b}} + {\rm{c}}} \right)}}\)