Question

Draw a plot showing the variation of (i) electric field (E) and (ii) electric potential (V) with the distance r due to a point charge Q.

Answer 1

We have to draw a plot for the variation of electric field $\left(E\right)$ and electric potential $\left(V\right)$ with distance $r$ due to a point charge $Q$.

We know that electric field $\left(E\right)$ for a point charge at a distance $r$ is $E=\frac{1}{4\pi {\epsilon }_0}\frac{Q}{r^2}$

i.e, $E$ varies with $r$ as: $E\propto \frac{1}{r^2}$

Electric potential due to a point charge $Q$ at a distance $r$ is $V=\frac{1}{4\pi {\epsilon }_0}\frac{Q}{r}$

i.e, $V\propto \frac{1}{r}$

So,