AT Cycle 27

🔴 2: Th 2/23a, 🟡 4: W 2/22 - Ampere's Law problems (1) 

Today, we'll start by comparing and contrasting Ampere's Law with Gauss's Law.  Then, after watching the homework videos below, we'll work on some Ampere's Law Problems:

    Required:  Ch 29 # 79, 81, 85, 11, 12, 21, 41, 43, 47, Giancoli Ch 28# 27-28

Homework:  Quiz on Magnetism Review and Biot-Savart problems next class - Thursday, February 23rd!   Upload PDF of your textbook solutions to the ✏️ Google Classroom assignment due Thursday, February 23rd at 10pm.   Make sure you've watched the first two Ampere's Law videos which were in the last post.  Then, watch the following videos on examples of the application of Ampere's Law:  

🟥 2: Th 2/23b, 🟨 4: Th 2/23 - Ampere's Law problems (2)

QUIZ Today on Magnetism Review and Biot-Savart!

Today, we'll continue working on some Ampere's Law Problems:

    Required:  Ch 29 # 79, 81, 85, 11, 12, 21, 41, 43, 47, Giancoli Ch 28# 27-28

With any time remaining, work on AP Problems from the next post.  

Homework:  If you have not finished watching any of the Ampere's Law videos in the previous post or have not completed any of the problems above, please do so.  Upload PDF of your textbook solutions to the ✏️ Google Classroom assignment due  Thursday, February 23rd.   Watch the following video showing two more examples of Ampere's Law.  After you watch both examples, finish the second example by finding the magnetic field as a function of r outside of the wire and finish the B vs. r graph.

❤️ 2: F 2/24, 💛 4: M 2/27a - 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:  ↩️ Pivot Interactives called "Magnetic Field in a Slinky" is due Tuesday, February 28th at 10pm.  

📕❗ 2: M 2/27, 📒❗ 4: M 2/27b - 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:  ↩️ Pivot Interactives called "Magnetic Field in a Slinky" is due Tuesday, February 28th 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: