W 4/23
Th 4/24
F 4/25
M 4/28
If you haven't finished the previous ๐ Mastering Physics "Ch 24 - magnetic force on a current" problems, start with that.ย ย
Then, we'll learn how moving charges create magnetic fields. We'll learn the last two right hand rules.
First, watch my video on "Current Create Magnetic Fields." It's a rather long video, but you can probably speed up parts of it. I recap the most important parts of the embedded videos, but watching the embedded videos will really build your understanding.
Then, we'll practice with concepts of a magnetic field created by a current by doing ๐ Mastering Physics "Ch 24 - current creates magnetic field" conceptual and multiple choice problems: #C8, C9, C10, C13, C24, MC30, MC31, P68.ย ย
Homework:ย Finish these ๐ Mastering Physics ย problems.ย QUIZ on all of magnetism up to this point on Monday, April 28th.
If moving charges produce magnetic fields, can magnetic fields move charges? Today, we'll learn how we can produce a current in a wire loop by changing the magnetic field through it. We'll introduce Lenz's Law and look at 3 (or really 4) steps:
Is there a changing number of magnetic field lines (aka magnetic flux) in the loop of wire?
How are the field lines changing? ("more/less lines to the right" for example)
The induced field opposes that change. ("more lines _____" opposite #2)
Use the right hand rule for the electromagnet/solenoid. (thumb = induced field, fingers curl = current)
We'll do some practice with Lenz's Law.
Watch all of "Intro to Induction and Lenz's Law."
Presentation:ย Lenz's Law
Then, each person is assigned just one problem from "Lenz's Law Practice Numbered". The answers are provided on the worksheet in parenthesis [(cw) for clockwise, (acw) for counter- or anti-clockwise]. There is a video link provided at the top of the document if you want examples of solutions. Check the post in โ๏ธ Google Classroom to find your assignment. Log onto ๐ Flipgrid using the link attached in โ๏ธ Google Classroom (should be able to click "Log in with Google" using your school wwprsd account, but manually create an account with your wwprsd email if you need to). And post your video solution. There's a 1 minute and 30 second maximum time for your video, but that should be plenty of time; my example video you see attached to the assignment in Flipgrid is only 45 seconds. You don't have to show your face on the video - just talk through the problem solution and show your right hand. Watch a few other peoples videos if you want or practice other problems from the document. Rewatch your video before posting to make sure that it is not backwards from the viewer's perspective.ย Hit Submit on this assignment in โ๏ธ Google Classroom. That's it for the assignment!ย
Homework:ย QUIZ on all of magnetism (does not include induction) on Monday, April 28th.ย Assignment due in ๐ Flipgrid by Sunday at 10pm.ย ย
Magnetism QUIZ Today!
Today, we'll introduce the quantitative formula for flux in a uniform magnetic field: ฮฆB = BAcosฮธ. We'll see how we can quantify the current created by a changing magnetic flux in a loop by looking at Faraday's Law: ฮต = -N ฮฮฆB/ฮt where I = ฮต/R (Ohm's Law).
First watch the "Faraday's Law" video.ย
Then, we'll practice induction problems by doing ๐ Mastering Physics "Ch 25 - Faraday's Law" problems: #C9, C12, C16, MC27, 9, 14, 16,17, 20, 21, 23.ย
Homework:ย Finish the above ๐ Mastering Physics problems by Monday, June 5th at 10pm.ย ย