Consider a synchronous generator connected to an infinite bus by two identical parallel transmission lines. The transient reactance x of the generator is 0.1 pu and the mechanical power input to it is constant at 1.0 pu. Due to some pr evious distur bance, the rotor angle (δ) is undergoing an undamped oscillation, with the maximum value of δ(t) equal to 130°. One of the parallel lines trips due to relay maloperation at an instant when δ(t) = 130° as shown in the figure given below. The maximum value of the per unit line reactance, x, such that the system does not lose synchronism subsequent to this tripping is