The single-line diagram of a 4-bus power network is shown in Figure 1, with all impedances of generators, ansformers and lines shown in per-unit to a common base. i. Determine the bus admittance matrix of the network Ybus by inspection. ii. Write the nodal equation in matrix form j0.2 1 j0.1 0.001+j0.4 j0.2 12 j0.09 0.001+j0.3 j0.3 j0.25 4 Figure 1