Generators and Motors
Generators turn motion into electricity; motors do the reverse.
About this topic
A generator spins a coil in a magnetic field, so induction produces an alternating voltage; slip rings and brushes connect it to the outside, and a commutator would give DC. A motor is the reverse: current in a coil in a field feels a force and turns.
In a motor, the forces on the two sides of the coil are opposite, creating a turning effect, and a split-ring commutator flips the current every half turn so the coil keeps rotating in the same direction. Output voltage of a generator rises with faster spinning, stronger magnets and more turns.
Generators in power stations are turned by steam, wind or water turbines. Motors drive fans, trains, washing machines and electric cars, and electric cars can recover energy by using the motor as a generator when braking.
A misconception is that generators create energy; they only convert kinetic energy to electrical energy, and the fuel or wind supplies the energy. Motors and generators are the same device run in opposite directions.
Key ideas
- Coil rotating in a field
- Slip rings or commutators
- AC vs DC
Quick check
Use cases: where Generators and Motors helps
- Homework: review the key idea behind Generators and Motors before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Generators and Motors without notes.
- Visual learning: play with the interactive lab to see how Generators and Motors changes when you adjust its inputs.
- Teaching a friend: explain Generators and Motors in your own words, then compare your version with the key ideas.
The same laws describe car crashes, sports, satellites and everyday machines.
Frequently asked questions
What is Generators and Motors?
Generators turn motion into electricity; motors do the reverse.
What will I learn in Generators and Motors?
Coil rotating in a field. Slip rings or commutators. AC vs DC.
Is Generators and Motors part of Physics?
Yes. It is one of 150 Physics topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Generators and Motors lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Generators and Motors?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.