A 500 W, 200 V compound motor has two field windings, one has a resistance of
0.03? and the other a resistance of 50 ?.
i) Draw and label a circuit diagram. Which winding should be connected to
the Z-ZZ terminal?
ii) If the armature resistance is 0.15 ?, calculate the emf when it draws an
armature current of 5A whilst running at 3000 rpm.
iii) When the load increases so that the motor draws a current of 10A, what is
the new speed of the machine? (assume the field shunt current does not
change – just the series field)