Exam Question

(a) State briefly, the meaning of the expressions 'Star-connected' as applied to three-phase a.c practice. What is the ratio of the maximum line voltage to the maximum phase voltage in each case (6)

(b) Determine the line current taken by a 440V, three-phase, star connected motor having an output of 45kW at 0.89 (lagging) power factor and an efficiency of 93 percent (10)