Question

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 radial distance $r$ from the centre of the nucleus as 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 $a$

Answer 1

Answer: (A)

Electric field at $r=R$

$E=\frac{KQ}{R^2};Q=$ Total charge within the nucleus $=Ze$
So, $E=\frac{KZe}{R^2}$
So, electric field is independent of $a..$