The nuclear charge (`Ze`) is non uniformlly distribute with in a nucleus of radius r. The charge density `rho(r)` (charge per unit volume) is dependent only on the radial distance r form the centre of the nucleus s shown in figure. The electric field is only along the radial direction.
The electric field at `r=R` is
A. independent of a
B. directly proportional to a
C. directly proportional to `a^(2)`
D. inversely proportional to a