when operating from a 230-V dc supply, a dc series motoroperates at 900 r/min with a line current of 75A. Its armeture-current is 0.13Ω, and its series-field resistance is0.09Ω. Due to saturation effects, the flux at an armaturecurrent of 25A is 45% of that at an armature current of 75A. Find the motor speed when the armature voltage is 230V and the armaturecurrent is 25A.