GATE Electrical Engineering (EE) 2015 Shift 2 Solved Paper

A three-phase, 11 kV, 50 Hz, 2 pole, star connected, cylindrical rotor synchronous motor is connected to an 11 kV, 50 Hz source. Its synchronous reactance is 50 Ω per phase, and its stator resistance is negligible. The motor has a constant field excitation. At a particular load torque, its stator current is 100 A at the unity power factor. If the load torque is increased so that the stator current is 120 A, then the load angle (in degrees) at this load is ________.