When operated from a 230-V dc supply, a dç series motor operates at 975 r/min with a line current of 90 A. Its armature-circuit resistance is 0.11 S2 and its series-field resistance is 0.08 S2. Due to saturation effects, the flux produced by an armature current of 30 A is 48 percent of that at an armature current of 90 A. Find the motor speed when the armature voltage is 230 V and the armature current is 30 A.