Question

A insulator sphere had a charge volume density 2.4 µC/m3 and it’s radius is
9.6 cm.What is the electric field at 5cm from it’s center ?

Answer 1

The electric field inside a charged sphere is given by:

$$E = \dfrac{4}{3}\rho kr$$

where $\rho = 2.4\times 10^{-6}C/m^3$ is the charge volume density, $k = 9\times 10^9N\cdot m^2/C^2$ is the constant. Thus, if $r = 5cm = 0.05m$, obtain:

$$E = \dfrac{4}{3}\rho kr = \dfrac{4}{3} 2.4\times 10^{-6}\cdot 9\times 10^9\cdot 0.05 =1.44\space V/m$$

Answer. 1.44 V/m.