What does an electric motor do?

Electric motors use electricity to create rotational motion.


This is because a coil of wire carrying a current, placed in a magnetic field, rotates due to the motor effect.

Answer in your head, out loud, or on paper, then tap the card to flip.

Name the device labelled A in the above diagram.

Split-ring commutator.

Answer in your head, out loud, or on paper, then tap the card to flip.

How does a split ring commutator ensure the coil rotates in one direction?

  1. The split-ring commutator swaps the positive and negative connections every half turn, meaning the direction of the current through the coil reverses every half turn.
  2. This means that the forces acting on the coil will always be acting in the same direction.
  3. This causes the coil to rotate continuously in one direction.

Answer in your head, out loud, or on paper, then tap the card to flip.

Give 4 ways to increase the speed of rotation in an electric motor.

  1. Increase the current in the coil.
  2. Add more turns to the coil.
  3. Use stronger magnets.
  4. Add a soft iron core to the coil.

Answer in your head, out loud, or on paper, then tap the card to flip.