AT Cycle 27
2/21 - 2/26
W 2/21
Th 2/22
F 2/23
M 2/26
🔴 2: Th 2/22a, 🟡 4: W 2/21, 🔵7: W 2/21 - slinky magnetic field lab
Today, we will start by talking about a different highly symmetric situation - a solenoid. We'll try to figure out an appropriate Amperian loop. The important part here is knowing WHY that Amperian loop works - think about the 4 criteria for a good Amperian loop. We'll look at a demo with iron filings.
Then, we'll start an in-person lab involving Ampere's Law. In this lab, we will explore factors that affect the magnetic field inside the solenoid. By inserting a magnetic field sensor between the coils of the Slinky, you can measure the magnetic field inside the coil. You will also find an experimental value for μ0 , the permeability of free space. The lab details can be found in the ↩️ Pivot Interactives called "Magnetic Field in a Slinky (in-person)."
Safety Precautions:
Turn all the knobs on the power supply counterclockwise before turning on.
This lab requires fairly large currents to flow through the wires and slinky. Only close the switch so the current flows when you are taking a measurement. The slinky, wires, and possibly the power supply may get hot if left on continuously. Make sure your output current from the power supply stays at or below 2.0A.
At the end of the lab, make sure to unplug the power supply and leave the plug on top so I can see it's unplugged from across the room.
Do not attempt to pick up the slinky with your hands, always use the stand to transport it. Do not allow the slinky to fall off the table or for any of the coils to be bent - this renders the slinky useless for other experiments.
If you miss class, email me to remind me to open the ↩️ Pivot Interactives called "Magnetic Field in a Slinky (virtual)" which allow you to do the lab without taking in-person data in class.
Homework: Quiz on Biot-Savart problems next class - Thursday, February 22nd! ↩️ Pivot Interactives called "Magnetic Field in a Slinky" is due Friday, February 23rd at 10pm.
🟥❗ 2: Th 2/22b, 🟨❗ 4: Th 2/22, 🟦❗ 7: Th 2/22a - slinky magnetic field lab
Quiz on Biot-Savart problems TODAY!
Today, we'll continue our in-person lab involving Ampere's Law. In this lab, we will explore factors that affect the magnetic field inside the solenoid. By inserting a magnetic field sensor between the coils of the Slinky, you can measure the magnetic field inside the coil. You will also find an experimental value for μ0 , the permeability of free space. The lab details can be found in the ↩️ Pivot Interactives called "Magnetic Field in a Slinky (in-person)."
Safety Precautions:
Turn all the knobs on the power supply counterclockwise before turning on.
This lab requires fairly large currents to flow through the wires and slinky. Only close the switch so the current flows when you are taking a measurement. The slinky, wires, and possibly the power supply may get hot if left on continuously. Make sure your output current from the power supply stays at or below 2.0A.
At the end of the lab, make sure to unplug the power supply and leave the plug on top so I can see it's unplugged from across the room.
Do not attempt to pick up the slinky with your hands, always use the stand to transport it. Do not allow the slinky to fall off the table or for any of the coils to be bent - this renders the slinky useless for other experiments.
If you miss class, email me to remind me to open the ↩️ Pivot Interactives called "Magnetic Field in a Slinky (virtual)" which allow you to do the lab without taking in-person data in class.
Homework: Unit Assessment on all of Magnetism Wednesday, February 28th. ↩️ Pivot Interactives called "Magnetic Field in a Slinky" is due Friday, February 23rd at 10pm. Watch the following video on finding the magnetic field inside a solenoid and toroid. I'm sorry this video is so much longer than normal (31 minutes), but my hope is that we talk about a lot of this stuff in class, especially when it comes to the solenoid. Definitely watch the last part about the toroid or the whole video if we don't get to talk about the solenoid in class:
❤️ 2: F 2/23, 💛 4: M 2/26a, 💙7: Th 2/22b - Ampere's Law AP problems (1)
Today, we'll continue class by finishing any problems that you didn't finish from the textbook. Then, we'll use what we've learned about Ampere's Law to solve some AP problems.
Required 1: 2000E3, 1993E1, 1979E2
Homework: Finish the above AP problems and upload to ✏️ Google Classroom by Monday, February 26th. Unit Assessment on all of Magnetism Wednesday, February 28th. Start reviewing induction concepts for next unit by watching videos on my AT Induction Review page.
📕 2: M 2/26, 📒 4: M 2/26b, 📘7: F 2/23 - Ampere's Laws AP problems (2)
Today, we'll start AP problems and do some AP multiple choice.
Required 2: 1983E3*, 1988E3a, multiple choice
* Add the following part to the 1983E3 problem:
(c.) (i.) Find an expression for the force per unit length between the two wires. (ii.) Is this force attractive or repulsive?
ANSWER: (c.)(i.) F/ℓ = μ0 I1 I2 / (4πa). (ii.) attractive
Multiple Choice Answers: 19-E, 47-D, 68-C, 65-D, 50-E, 42-E
Then, we'll do some Ampere's Law problems from the textbook:
Required: Halliday Ch 29 #35, 49, 52, 53, 54
Homework: Upload a PDF of your solutions to the 2 AP problems and textbook problems above to ✏️ Google Classroom assignment due Tuesday, February 27th. Unit Assessment on all of Magnetism Wednesday, February 28th. Review induction concepts for next unit by watching videos on my AT Induction Review page. Period 2 - maybe re-watch the Mass Spectrometer video as review for the test.