A series motor operates in the linear region in which the flux is proportional to the armature current. When the armature current is 12A, the motor speed is 600 rpm. The line voltage is 120V, the armature resistance is 0.7 Ω and the series field-winding resistance is 0.5Ω. What is the torque developed by the motor? For the motor to operate at a speed of 2400rpm, determine (a) the armature current and (b) the driving torque.