Calculate the inductance and capacitance per phase for an overhead line given its length, conductor diameter, and assuming free space.

Here's how to calculate the inductance and capacitance per phase for the given overhead line:

Given:
Line length $L_{line} = 18 \text{ km} = 18 \times 10^3 \text{ m}$
Conductor diameter $d = 1 \text{ cm} = 0.01 \text{ m}$
Conductor radius $r = d/2 = 0.005 \text{ m}$

Constants:
Permeability of free space $\mu_0 = 4\pi \times 10^{-7} \text{ H/m}$
Permittivity of free space $\epsilon_0 = 8.854 \times 10^{-12} \text{ F/m}$

Formulas:
Inductance per phase per meter: $L_{per\_meter} = \frac{\mu_0}{2\pi} \ln\left(\frac{D_{eq}}{r'}\right)$
Cap