During a power failure, a domestic household uninterruptible power supply (UPS) supplies AC power to a limited number of lights and fans in various rooms. As per a NewtonRaphson load-flow formulation, the UPS would be represented as a

The bus impedance matrix of a 3-bus system (in pu) is

$$ Z_{\text {bus }}=\left[\begin{array}{lll} j 0.059 & j 0.061 & j 0.038 \\ j 0.061 & j 0.093 & j 0.066 \\ j 0.038 & j 0.066 & j 0.110 \end{array}\right] $$

A symmetrical fault (through a fault impedance of $j 0.007$ p.u.) occurs at bus 2 . Neglecting pre-fault loading conditions, the voltage at bus 1 , during the fault is __________ p.u. (round off to three decimal places).