A short-shunt compound generator has a terminal voltage of 240 V when it delivers 125 A. The shunt-field current is 5 A, the armature resistance is 25 mohm, and the series field resistance is 15 mohm. At its operating speed of 600 rpm, the rotational loss is 3 kW. Determine its efficiency and the torque supplied by the prime mover. Sketch its power flow diagram.