Question

In three-point starter, as a starting handle is rotated __________

(a) The resistance is added into armature circuit

(b) The resistance is removed from field circuit

(c) The resistance is added into field circuit

(d) Resistance is neither added nor removed

The question was posed to me in an online quiz.

The origin of the question is Starting of DC Motors in section DC Motors of DC Machines

Answer 1

Correct option is (c) The resistance is added into field circuit

The best I can explain: The starting resistance is arranged in steps between conducting raised studs. As the starting handle is rotated about its fulcrum, it moves from one stud to the next, one resistance step is cut out, and it gets added to the field circuit.