IIT JEE Advanced 2012 Paper 1

For a uniformly charged spherical shell, the graph due to electric field lines (inside) and the electric potential (inside) are depicted in Figs. (a) and (b), respectively.

• Electric field [Fig. (a)]:
Einside = 0, for r < R; Eoutside =

kQ

r2

, for r ≥ R
• Electric potential [Fig. (b)]:
Vinside =

kQ

R

, for r ≤ R; Voutside =

kQ

r

, for r ≥ R
where k =

1

(4πε0)

. Hence, the correct graph is the onedepicted in option (D). The dotted line shows the resultant graph of V(r) versus r.