# AT Cycle 24

## 2/4 - 2/9

F 2/4

M 2/7

T 2/8

W 2/9

### π΄ 1: F 2/4, π‘ 3: F 2/4 - dielectrics

Today, we'll talk about how dielectrics can increase capacitance. We'll look at the work to insert or remove a dielectric with a problem. Watch the following video for details on dielectrics. Then do problems from the Giancoli textbook Chapter 24:

Required: Giancoli Ch 24 Example 24-8 and Problems #56, 57, 85, 87

Here's a list of the things you should be able to do by now:

• Know how to derive the charging and discharging equations (and also know what they are without doing the derivation)

• Know how to get the time constant from a graph two different ways

• Know what happens at t=0+ and t=β when charging or discharging

• Derive the energy stored in capacitor equation

• Know how a dielectric changes electric field, capacitance, and energy stored

• Know the two different types of problems when inserting dielectrics

• Derive the βCAKEdβ equation

Homework: If you need to review dielectrics, you may review the video below:

### π₯ 1: T 2/8 lab, π¨ 3: M 2/7 lab - internal resistance lab

Today, we'll do a lab where we explore the terms: emf, internal resistance, and terminal voltage.

Safety Precautions:

• Make sure your circuit is only connected to the battery for brief (~1 second) periods of time to avoid overheating and wasting your battery.

After finishing the lab, do textbook problems Chapter 27 #10, 14 and Giancoli Chapter 26 #1, 2, 4. Then do 2015E2 to check for your understanding. Watch the homework videos first if you prefer.

Handouts: EMF & Internal Resistance Lab

Homework: LAB QUIZ on internal resistance and lab practical on Thursday, February 10th. Finish the internal resistance lab.

If you have any trouble understanding the analysis, watch the following video:

Also, everyone should watch this video on maximizing the power for an external resistor:

### β€οΈ 1: W 2/9, π 3: T 2/8 - more practice AP Problems (1)

Today, if you have not finished the internal resistance lab or any of the associated problems, start with that.

Then, we'll do some more practice AP Problems:

Required: 2002E2, 2003E2, 1986E2, 1988E2 (don't worry about part e), 1989E3

We'll have time to work on these problems again next class after your lab quiz.

Homework: LAB QUIZ on internal resistance and lab practical next class - Thursday, February 10th. Read and process the following website for yourself on series and parallel capacitors: derivation for series & parallel capacitor equations. Also, take a look at this additional useful information on circuits that Mr. Sierzega put together (must be signed into wwprsd Google account).