User's Manual

012-07210A Permanent Magnet Motor

wire connected to the +

terminal of the power

supply

When you wrap

your fingers in the

direction of the flow

of the electric

current, your

thumb points

towards the north

pole of the

magnetic field.

Draw arrows indicating the direction of

current flow.

Indicate which pole is north (N) or south (S).

Teacher’s Guide

Answers To Questions:

Part A

6. a) Yes.

b) They add together to create a greater effect.

7. No.

8. a) Yes.

b) True.

c) False.

d) The location of the armature’s north pole alternates between ends of the armature as the + lead

touches the alternate sides of the split ring commutator.

e) The current is alternating in the coils because one side of the split ring commutator sends the

current in one direction in the wire, while the other side sends it in the opposite direction in the

wire.

Experiment 1:

 Remind students not to prolong situations when the armature is not spinning and the power

is connected—the coils will overheat.

Figure 1. 4, labeled

direction of wire

wrapping on the coil