A single phase overhead transmission line consists of two solid aluminum conductors having a radius of $3$cm with a spacing of $3\mathrm{.}5$m between centers. a$)$ determine the total line inductance in mH$/$m$.$ b$)$ gven the operating frequency to be $60$Hz$,$ find the total inductave reactance of the line in ohm$/$m and in ohm$/$mi$.$ c$)$ if the spacing is doubled in $7$m$,$ how does the reactance change?