|
In a rush? Need only a quick review? Watch the 3 min video Otherwise, please move on... |
|
If a conductor experiences a changing flux, and thus experiences and EMF, if the charges are free to flow, currents are induced. In solid materials such as pipes and sheets of metal, these currents become eddy currents. However these eddy currents will therefore also generate their own magnetic fields thereby interacting with the magnetic field that generated them. This leads to an important principle called Lenz' Law.
Lets' start by looking a a brief overview of what Lenz' Law is all about.
Lets' start by looking a a brief overview of what Lenz' Law is all about.
|
There are a number of great demonstrations that work on the principle of Lenz's Law. Here I examine a few of them |
|
We now examine an Physics of Lenz' Law called Electromagnetic Braking
The first looks at the example of dropping a magnet down a pipe, which you saw above.
Similar to the video above, we now looking at electromagnetic braking from a different perspective.
Again, examining the physics principles
Again, examining the physics principles
In summary
Lenz's Law states that if eddy current are induced due to a rate of change of flux, the polarity of those eddy current will oppose the polarity which induced this. This ensure it is consistent with the Conservation of Energy.
We can use this principle for things such as electromagnetic braking.
Lenz's Law states that if eddy current are induced due to a rate of change of flux, the polarity of those eddy current will oppose the polarity which induced this. This ensure it is consistent with the Conservation of Energy.
We can use this principle for things such as electromagnetic braking.
How well do you know induction?
|
You should be now at a point to understand the key concepts in electromagnetic induction - flux, Faraday's Law and Lenz' Law.
Test your understanding by doing the quiz and try to get full marks Then check your understanding if necessary with the video |
|
