The two-bus power system shown in figure (i) has one alternator supplying a synchronous motor load through a $Y- \Delta$ transformer. The positive, negative and zero-sequence diagrams of the system are shown in figures (ii), (iii) and (iv), respectively. All reactances in the sequence diagrams are in p.u. For a bolted lineto-line fault (fault impedance = zero) between phases ' $b$ ' and ' $c$ ' at bus $1$, neglecting all pre-fault currents, the magnitude of the fault current (from phase ' $b$ ' to ' $c$ ') in p.u. is__________ (Round off to $2$ decimal places).
