6-9 In a 2-pole, three-phase ac machine, lg = 1.5 mm and N₂ = 100. During a balanced, sinusoidal, 60-Hz steady state with the rotor electrically open-circuited, the peak of the magnetizing current in each phase is 10 A. Assume that at t = 0, the phase-a current is at its positive peak. Calculate the flux-density distribution space vector as a function of time. What is the speed of its rotation?

Fig: 1