A shunt motor has the following ratings: 75 kW, 240 V, 1750 rpm, 300 A. The motor is supplied with 240 V source (constant) at its armature terminals. Its armature resistance is 0.0144 [O]. At rated current Ia = 300 A, the motor runs at rated speed of 1750 rpm.
(a) Compute the output power Pout, torque T, and speed sm of the motor at armature current of Ia = 0 [A].
(b) Repeat the solution for armature current Ia = 150 [A].
Units: Find the speed sm in [rad/s], the ouput power Pout in [kW], and the torque T in [N m].
Conversion factors: 1 rpm = 1 rev/min. 1 rev = 2p rad. 60 s = 1 min.