List of top Power Systems Questions on Electric field distribution and insulators asked in GATE EE

In the circuit shown below, a three-phase star-connected unbalanced load is connected to a balanced three-phase supply of 100\(\sqrt{3}\) V with phase sequence ABC. The star connected load has \( Z_A = 10 \, \Omega \) and \( Z_B = 20 \angle 60^\circ \, \Omega \). The value of \( Z_C \) in \( \Omega \), for which the voltage difference across the nodes \( n \) and \( n' \) is zero, is
The valid positive, negative and zero sequence impedances (in p.u.), respectively, for a 220 kV, fully transposed three-phase transmission line, from the given choices are