What difference can we see in the inductance of a transmission line if we change the conductor

Question:

What difference can we see in the inductance of a transmission line if we change the conductor arrangements from the two-bundling to three-bundling, as can be seen in Fig. 3.11? The Geometrical Mean Radius (GMR) of each conductor is $r^{\prime}$ and $D=4 r^{\prime}$. Herein, the distance between the phases is kept constant.

1) A decrease about $\frac{2}{3} \times 10^{-7} \ln (2)$

2) No change

3) An increase about $\frac{2}{3} \times 10^{-7} \ln (2)$

4) An increase about $\frac{3}{2} \times 10^{-7} \ln (2)$

image text in transcribed