A dc series motor, with a design constant Ka = 40 and flux per pole of 46.15 mWb, operates at 200 V while taking a current of 325 A. The total series-field and armature-circuit resistances are 25 and 50 m Ω, respectively. The core loss is 220 W; friction and wind age loss is 40 W. Determine:
(a) The electromagnetic torque developed.
(b) The motor speed.
(c) The mechanical power output.
(d) The motor efficiency.