How the Electric Motor Works

Question 1

What happens if we take a coil that has currents in opposite directions on either side and put it in a magnetic field?

Answer 1

Since the currents are in opposite directions, that means the forces generated due to the motor effect will be as well. These opposite forces on either side will cause rotation.

Question 2

What is the problem we have when we don’t have a split-ring commutator?

Answer 2

As the coil rotates 180 degrees, this will turn the coil upside down and therefore the currents will be inverted which will create inverted forces that will turn it back 180 to where it started. This means it wouldn’t ever turn 360 degrees.

Question 3

How does a split-ring commutator help?

Answer 3

It does this by swapping the positive and negative connections which results in the direction of the current swapping every half term which makes the forces acting on the coil to always be acting in the same direction allowing the coil to spin continuously in the same direction.

Question 4

How to increase the rotation speed of the coil in the motor effect?

Answer 4

• Increasing current
• Adding more turns to the coil
• Increasing magnetic flux density