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

Options

A. independent of a
B. directly proportional to a
C. directly proportional to `a^(2)`
D. inversely proportional to a

Answer

A

Explanation

`E=(1)/(4 pi in _(0))(Q)/(R^(2)),Q=` total charge `e=Ze`

`rArrE=(Ze)/(4 pi inR^(2))`
`rArr E` at `r=R` is independent of a