Question

A charge which has a magnitude of 18 nanoCoulomb produces an electric field. At a distance r the strength of Electric field is equal to . How far is the source charge from the charge?

Answer 1

The strength of electric field $E$ produced by the charge $q$ at a distance $r$ is given by the equation:

$$E = \dfrac{1}{4\pi\varepsilon_0}\dfrac{q}{r^2}$$

where $\varepsilon_0 = 8.85\cdot 10^{-12} F/m$ is the permittivity of free space.

Thus, for the given charge and strength of electric field the distance will be:

$$r = \sqrt{\dfrac{q}{4\pi\varepsilon_0E}}$$

Answer. $r = \sqrt{\dfrac{q}{4\pi\varepsilon_0E}}.$