A 240-V, 900-rpm, dc series motor takes 25 A at full load. The armature and field-winding resistances are 0.2 ohm and 0.3 ohm, respectively. The rotational loss is 300 W. Calculate (a) the power developed, (b) the power output, (c) the available torque, (d) the copper loss, and (e) the efficiency. If the pulley diameter is 20 cm, what is the force exerted by the motor at the rim of the pulley?