Question

Find the electric field inside a hollow plastic ball of radius R that has charge Q uniformly distributed on its outer surface. Give your answer as a multiple of Q/ε0.Express your answer in terms of some or all of the variables R, r and the constant π.

Answer 1

Answer:

The electric field inside the hollow plastic ball is zero.

Explanation:

According to Gauss's law, the electric field at the closed Gaussian surface $S$ is given by

$\oint_S {E_n \cdot dA = \dfrac{Q_{enc}}{{\varepsilon _0 }}}$

Now, to find the electric field inside the hollow plastic ball, we choose a spherical Gaussian surface inside the ball. And since all of the charge lies on the surface of the ball, the Gaussian surface does not enclose any charge; therefore, the Gauss's law gives:

$E(4\pi r^2)= \dfrac{Q_{enc}}{{\varepsilon _0 }}}$

$E(4\pi r^2)=0 \\\\\boxed{E = 0}$

The electric field inside the hollow plastic ball is zero.