b) A 3-phase, 6600-V, 6-pole, 50-Hz, star-connected synchronous motor has a synchronous impedance of 0 + j300 per phase. At rated load the armature current is 100 A at 0.9 p.f. leading. Neglecting losses: i. Determine the e.m.f. (E), the load angle in mechanical degrees and the rated torque. ii. What increase of excitation will be required to sustain a torque overload of 25000 Nm without falling out of step? iii. With this new excitation, what would be the values of current, power factor and load angle at rated torque? iv. With this new excitation, what reduction of terminal voltage would be permissible so that the machine would just stay in synchronism at rated torque? V. With this new excitation, and rated terminal voltage, what would be the value of current if the load was removed altogether? [15 Marks]