The electrostatic potential inside a charged spherical ball is given by φ = a r² + b where r is the distance from the center and a,b are constants. Then the charge density inside the ball is:

Electrostatics: JEE Main 2011 Physics question

JEE Main 2011 · Annual, Paper 1 · Q7000

JEE Main 2011Annual, Paper 1PhysicsMediumElectrostatics167× since 2002

The electrostatic potential inside a charged spherical ball is given by

\phi = a{r^2} + b

where

r

is the distance from the center and

a,b

are constants. Then the charge density inside the ball is: