Question

a spark plug in an aoutomobile engine consists of two metal conductors that are separated by a distance of 0.5mm. When an electric spark jumps between them, the magnitude of the electric field is 4.0x10⁷V/m. What is the magnitude of the potential difference V between the conductors?

Answer 1

The potential difference (in case of uniform electric field) is given as follows:

$$\Delta \varphi = Ed$$

where $E = 4\times 10^{7}V/m$ is the electric field, and $d = 0.5mm = 0.0005m$ is the distance between two conductors. Thus, obtain:

$$\Delta \varphi =4\times 10^{7}V/m\cdot 0.0005m = 2\times 10^4V$$

Answer. $2\times 10^4V$.