The severity of line-to-ground and three-phase faults at the terminals of unloaded synchronous generator is to be same. If the terminal voltage is 1.0 pu and Z1 = Z2 = j0. 1 pu, Z0 = j0.05 pu for the alternator, then the required inductive reactance for neutral grounding is
1
0.0166 pu
2
0.05 pu
3
0.1 pu
4
0.15 pu