Trent builds a model electric motor. When he connects a battery to the motor, the motor spins through a half rotation and stops.
Answer
A
replacing the battery, because it is not providing current
B
installing new brushes, because they are not making a good connection
C
checking the commutator, because the current is not reversing
D
adding more wire coils in the armature, because the electromagnet is too weak
Explanation
A DC motor’s commutator reverses the current in the armature every half turn so the motor keeps spinning in the same direction. If the motor turns half a rotation and then stops, the commutator may not be reversing the current. Checking the commutator is therefore the best choice.
AI-written and checked against the verified answer.