At the end of the list under each concept is the assessment for that concept. If you can complete the assessment successfully, you are good for that concept and can move on. You will have as many tries as you want at the concept assessments you can edit your answers immediately or just resubmit them any time. Everything is due the last official day of school, 5/21, but they will say "missing" in Synergy until you do them. I update Synergy once a day.
Charge and Charge Conservation
Khan Academy does a really good job with this topic, and I see no reason to reinvent the wheel here. So, make your way through the first two sections of their unit here: Khan Academy Electric Charge and Electric Force. You don't have to do the practice problems if you don't want to - they are not graded in any way. You could just watch the videos and be pretty good.I will add a couple of clarifying facts:
- The "net" charge or "total" charge of a large object is the sum of all of the little charges inside of it
- all charge must be a whole number multiple of the "elemental charge" - the charge of a proton or electron. So if someone tells you that they found something with a charge of 4.5 x (elemental charge), they made a mistake.
Assessment: Charge and Charge Conservation.
Coulomb's Law
I am less enthralled with Khan Academy's instruction on Coulomb's Law - they have too much math. So you can look at it if you want - it is the third section of the unit at Khan Academy Electric Charge and Electric Force. But I would stop the video when they start doing math.Here is the PowerPoint we would have done in class: Coulomb's Law .
Here is me reading my own PowerPoint: Volkening reads her own Coulomb's Law PowerPoint
Most problems you see about Coulomb's Law are of two types. One type is the "if I changed this, what would be the new force?" type problem, which is on the PowerPoint and in the practice problems on Khan Academy. Another type is more visual, and asks where you'd place a charge to get a certain resultant force on that charge, or what the resultant force would look like. Here are some examples of that type of problem:
Placing a charge so the net force is zero
What is the direction of the net force on a charge?
Assessment: Coulomb's Law .
Electric Potential
ASU Prep Digital has a great overview of electric potential, current, resistance, and circuits in general here: ASU Prep Digital H04: Electric MeasurementsHere is the specific information on electric potential that we would have gone over in class: Electric Potential Energy and Electric Potential Powerpoint
Here is a video of me reading my own Powerpoint: Volkening reads her own Electric Potential Powerpoint
Assessment: Ue and V.
Electric Current
You may already have a pretty good feel for current from ASU Prep Digital H04: Electric Measurements
But here is my powerpoint: Electric Current
And here is me reading it: Volkening reads her own Electric Current Powerpoint
The video I refer to at the beginning is here: Electric Fence Experiment Ends as Expected
The video I refer to at the beginning is here: Electric Fence Experiment Ends as Expected
Electric Resistance
Here is a video of me talking through that PowerPoint, saying stupid things and rambling a bit (like usual): Volkening Reads Her Own Resistance Powerpoint
Here is Khan Academy explaining from scratch, and from a different starting point: Khan Academy Resistivity and Conductivity . Just ignore the stuff about conductivity - it isn't something you need to know.
Assessment: Electric Resistance.
Circuit Diagrams
Circuit diagrams are meant to represent connections between circuit elements, but they may not look exactly like the physical thing they represent. For example, instead of actually drawing a battery, we use a symbol that represents a battery, sort of like how on a road map we use a symbol for a rest area instead of actually drawing the rest area.There are literally hundreds, if not thousands, of symbols, and a lot of them have regional variations. These are the only symbols we'll really be using for this class: Circuit diagram symbols
Here are some videos that may help:
Drawing Circuit Diagrams Examples
Circuit Diagrams: Does a Current Go Through the Resistor?
Assessment: Circuit Diagrams.
Ohm's Law
ASU Prep Digital does a good job of walking you through an online version of the lab that we were going to do in class with real resistors, batteries, and a multimeter (can be an ammeter, voltmeter, or ohmmeter). So go here: I02 Series Circuit Investigation - Ohm's Law and do the investigation. Work through the notes after that to actually get Ohm's Law.Assessment: Ohm's Law.
Series Circuits
ASU Prep Digital: I03 Series Circuits and Potential Difference does a great job here.Assessment: Series Circuits.
Parallel Circuits
Optional: ASU Prep Digital I04 Parallel Circuit Investigation . This is kind of fun, and we would have done something similar in class with real little lightbulbs, but you can skip it if you want.
What you really need to know about parallel circuits is here: ASU Prep Digital I05 Parallel Circuits and Equivalent Resistance.
Can't tell when resistors are parallel or not? Try this trick: Color Coding Potentials
I really like Khan Academy's video about electric power: Khan Academy Electric PowerCan't tell when resistors are parallel or not? Try this trick: Color Coding Potentials
A lot of power questions will take the format of "how much money will it cost to run this appliance for this many hours a day for this many days?" So here is an old video of one of those problems:
Find the cost of running a TV for a certain amount of time
Assessment: Electrical Power.
Compound Circuits
To be able to solve compound circuits, you need to know Kirchoff's Rules.
Khan Academy: Junction Rule . Both the video and the practice are worth doing The video can really be stopped at 2:57.
I don't like their video for the Loop Rule as much. Their practice is pretty good, though. Khan Academy Practice: Loop Rule. Their summary is also not bad: Kirchoff's Loop Rule Review from Khan Academy
Here is a video of me explaining the Loop Rule: Kirchoff's Loop Rule
With these tools, you will be able to "solve" any circuit - that is, you will be able to calculate the resistance, current through, and potential difference across every resistor in the circuit.
I have a system for solving a circuit that seems to work pretty well. I split it up into two videos:
Solving Compound Circuits Part 1: Simplifying the Circuit (total R)
Solving Compound Circuits Parts 2-4: Everything Else
Here's all the same stuff, but in strictly text from The Physics Classroom: Combination Circuits
Here are some example problems being solved:
Example 1
Example 2
Khan Academy has some worked examples as well:
Current through resistor in parallel
Current due to closing a switch. This is a different sort of problem that is usually very popular on standardized tests.
Solving Compound Circuits Part 1: Simplifying the Circuit (total R)
Solving Compound Circuits Parts 2-4: Everything Else
Here's all the same stuff, but in strictly text from The Physics Classroom: Combination Circuits
Here are some example problems being solved:
Example 1
Example 2
Khan Academy has some worked examples as well:
Current through resistor in parallel
Current due to closing a switch. This is a different sort of problem that is usually very popular on standardized tests.
Volkening's students: if you have completed all of the online assessments above, you can take this Electricity Unit Test. This is completely optional. You'll only get to take it once, but I'll only put in the grade if it makes your grade go up. All of the problems are taken from the previous online assessments, except I've changed the numbers or wording a little. There are 10 problems worth two points each, and it does go into Synergy as a test.
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