Assuming that a group of n conductors
carrying linear charge densities
q_{1}, q_{2}, …, q_{n}
are located above the ground plane, the voltage of conductor i to ground is

$V_{i}=\frac{q_{1}ln\left(\frac{D_{i1}}{d_{i1}}\right)+\cdots+q_{i}ln\left(% \frac{D_{ii}}{d_{i}}\right)+\cdots+q_{n}ln\left(\frac{D_{in}}{d_{in}}\right)}{% 2\pi\epsilon}$ | (31) |

where

q_{i} is the charge of conductor i in coulombs/meter.

d_{i} is the radius of conductor i.

D_{ii} is the distance between conductor i and its image
(i.e. 2h_{i} in Figure
1).

d_{ij} is the distance between conductor i and conductor
j.

D_{ij} is the distance between conductor i and the image of
conductor j as illustrated in Figure
1.

$\epsilon$ is the permittivity of the medium.

Note: The distances associated with each logarithmic ratio
(e.g. d_{i} and D_{ii} or d_{in}
and D_{in}) of Equation
31 must be expressed in the same units.