F 2/28
M 3/3
T 3/4
W 3/5
Unit Assessment on all of Magnetism Today!
Homework: Make sure you have reviewed all of the induction topics you should have learned last year on my AT Induction Review page.
In groups today, we'll try to compile a list of facts and equations that you should know about induction. We'll collect all of the ideas and make sure you understand the following:
Lenz's Law (to find direction of induced current)
Faraday's Law of Induction (to find magnitude and direction of induced current)
Motional e.m.f. (moving bar through magnetic field)
Transformers (ideal transformer equation)
how motors work
how generators work
Take notes on all of above and upload pictures of your notes to ✏️ Google Classroom assignment.
During 2nd hour, we'll review Lenz's Law. This is one of the most important topics for the AP exam. We'll review Lenz's Law (presentation). We'll briefly discuss ways of inducing a current in a loop of wire. We'll review Lenz's Law which states, "An induced emf gives rise to a current whose magnetic field opposes the original change in flux." We'll see how we might use this concept to generate electricity to power a lightbulb. We'll take turns in groups collaboratively practicing at least one from each page on the Lenz's Law Practice page below.
Homework: Make sure you have reviewed all of the induction topics you should have learned last year on my AT Induction Review page. Upload pictures of your induction notes to ✏️ Google Classroom assignment due Tuesday at 10pm.
Today, we'll explore Faraday's Law with simulations and video demonstrations. Record your observations for each simulation/demonstration in ✏️ Google Classroom.
We'll start with two different on-line simulations from the University of Colorado PhET group.
INVESTIGATION 1:
First, link to the simulation: https://phet.colorado.edu/en/simulation/faradays-law
What happens when a magnet moves through a coil in which a current can flow?
Move the magnet at a relatively constant frequency back and forth through the coil. The voltage displayed is proportional to the current flowing in the coil. Watch the reading of the voltmeter. What happens
as you move the magnet through the coils with different number of loops,
as you change the frequency and therefore the speed of the magnet for a given number of loops, and
as you change the polarity of the magnet?
INVESTIGATION 2:
Second, link to the simulation: http://phet.colorado.edu/en/simulation/faraday
Using the window called Pickup Coil, investigate what you can about induction. Make a list of variables that affect the amount and direction of the induced current. Qualitatively describe how these variables affect the amount and direction of the induced current. Upload your explanation to ✏️ Google Classroom.
INVESTIGATION 3:
Watch this video of Faraday's Law - Demonstrated & Explained. Using your own words and diagrams, explain the demonstration that starts at 2:57. Upload your explanation to ✏️ Google Classroom by Sunday at 10pm.
INVESTIGATION 4 (optional but suggested):
With any time remaining, watch this video on Lenz's Law demonstrations, and explain at least what you observe in the demo from 1:00-3:02. Upload your explanation to ✏️ Google Classroom by Sunday at 10pm. If you still have time, watch and try to make sense of the other demonstrations in this video.
Homework: Quiz on Induction Review on Thursday, March 6th. Finish all of the above in ✏️ Google Classroom by Wednesday, March 5th at 10pm.