Mathematics · Electrical Machines

A 3-phase, 415 V, 4-pole, 50 Hz induction motor draws 5 times the rated current at rated voltage during starting. It is required to bring down the starting current from the supply to 2 times the rated current using a 3-phase autotransformer. If the magnetizing impedance of the induction motor and the no-load current of the autotransformer are neglected, what is the transformation ratio of the autotransformer? (Round off to two decimal places)