A generator delivers power of 1.0 p.u. to an infinite bus through a purely reactive network. The maximum power that could be delivered by the generator is 2.0 p.u. A three phase fault occurs at the terminals of the generator which reduces the generator output to zero. The fault is cleared after second. The original network is then restored. The maximum swing of the rotor angle is found to be electrical degree. Then the rotor angle in electrical degrees at t = is