AT Cycle 25

🔴 2: T 2/18, 🟡 4: T 2/18, 🔵 8: T 2/18 - Biot-Savart problems (2)

Today, you'll utilize what you learned from the video last night in order to calculate the magnetic field due to a current-carrying wire.  You'll look at problems from section 29-1 of your textbook, apply your problem-solving skills, and collaborate with your classmates to solve difficult problems.  

    Required: Ch 29 #7, 4, 56, Giancoli Ch 28 #36
    Enrichment: Ch 29 #32, 33

Also, pick a couple Biot-Savart problems from the problem section 29-1 at your level of math (if you are in multivariable calculus, you should be working on the 3 dot problems).  For Biot-Savart, also review "Current loop" example 28-10 from Giancoli; copy the solution in your notebook.  

If there's time remaining, watch the homework videos below.

Homework:   RC Circuits Multiple Choice Section (16MCQ in 20 min) on Thursday, February 20th.  QUIZ on Magnetism Review (~24 MCQ in 30 min) also on Thursday, February 20th.  Quiz on Biot-Savart (~10 MCQ + 1 two-page FRQ) on Monday, February 24th!   Finish Biot-Savart required problems above.  Watch the following videos on Ampere's Law:  

🟥❗ 2: Th 2/20 lab, 🟨 4: W 2/19 lab, 🟦 8: W 2/19 lab - Ampere's Law problems

Period 2:  RC Circuits Multiple Choice Section Today.  Quiz on Magnetism Review also Today.  

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:  RC Circuits Multiple Choice Section on Thursday, February 20th.  QUIZ on Magnetism Review also on Thursday, February 20th.  Quiz on Biot-Savart on Monday, February 24th!   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: F 2/21, 💛❗ 4: Th 2/20, 💙❗ 8: Th 2/20 - slinky magnetic field lab (1)

Periods 4 & 8:  RC Circuits Multiple Choice Section Today.  Quiz on Magnetism Review also Today.  

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 - Monday, February 24th!  ↩️ Pivot Interactives called "Magnetic Field in a Slinky" is due Monday, February 25th at 10pm.