The bus admittance matrix of the network in per unit is if impedance in P.U. is given
1
\(\left[ {\begin{array}{*{20}{c}} {10}&{ - 5}\\ { - 5}&5 \end{array}} \right]\)
2
\(\left[ {\begin{array}{*{20}{c}} 5&{ - 5}\\ { - 5}&{10} \end{array}} \right]\)
3
\(\left[ {\begin{array}{*{20}{c}} { - 10}&5\\ 5&{ - 5} \end{array}} \right]\)
4
\(\left[ {\begin{array}{*{20}{c}} { - 5}&5\\ 5&{ - 10} \end{array}} \right]\)