I am varying loss tangent of the surrounding medium, keeping the relative permitivity of the medium constant. I am getting a capacitance per unit length value that is same for any non-zero value of loss tangent, but different when loss tangent is 0. How is this possible? The graph below should explain my doubt clearly. Note: I have taken hypothetical values for loss tangent values.
Does capacitance per unit length change with change in loss tangent of surrounding medium?
If the permittivity of the medium remains constant then no, capacitance per unit length change does not change with loss tangent variations.
It's the same for inductance per unit length - having greater copper losses does not affect the inductance of a wire.