A Series of 3 Uncharged Concentric Spherical Conducting Shells Surround $\infty$

Multiple Choice

A series of 3 uncharged concentric spherical conducting shells surround a small central charge q.The potential at a point outside the third shell,at distance r from the center,and relative to V = 0 at $\infty$ ,is

A) $- \frac { 3 k _ { e } q } { r }$ .
B) $- \frac { ( \ln 3 ) k _ { e } q } { r }$ .
C) $+ \frac { k _ { e } q } { r }$ .
D) $+ \frac { ( \ln 3 ) k _ { e } q } { r }$ .
E) $+ \frac { 3 k _ { e } q } { r }$ .