Question

What do electric field lines provide information about?

Answer 1

Information provided by electric field:

1. The electric field is defined mathematically as a vector field that can be associated with each point in space, the force per unit charge exerted on a positive test charge at rest at that point.

2. The electric field is generated by the electric charge or by time-varying magnetic fields. In the case of the atomic scale, the electric field is responsible for the attractive forces between the atomic nucleus and electrons which hold them together

3. The electric field around an electric charge is given by the formula:

$\overrightarrow{\mathrm{E}}=\frac{1}{4{\mathrm{\pi \epsilon }}_0}\frac{\mathrm{q}}{{\mathrm{r}}^3}\hat{\mathrm{r}}$
Where, $\frac{1}{4{\mathrm{\pi \epsilon }}_0}$ is the constant, $\mathrm{q}$ is the test charge, $\mathrm{r}$ is the distance of the point charge from the source charge, $\hat{\mathrm{r}}$ is the unit vector showing the direction of the electric field.

4. We can see from the above expression or formulation that the electric field lines provide information about the electric field that enables us to understand the kind of charge and the direction of the electric field.

5. A schematic diagram of an electric field line from an isolated charge is shown below.

6. The direction of the field is taken as the direction of the force which is exerted on the positive charge.

7. The electric field is radially outwards from the positive charge and radially in towards the negative point charge.

Hence, the electric field lines provide information about the direction of the electric field, the strength of an electric field, and the nature of the electric charge.