Electrostatics

The nuclear charge (Ze) is non-uniformly distributed within a nucleus of radius R. The charge density \(\rho(r)\) [charge per unit volume] is dependent only on the radical distance r from the centre of the nucleus as shown in figure. The electric field is only along the radial direction.

For a = 0, the value of d (maximum value of \(\rho\) as shown in the figure) is