Electric Current is the flow of electric charge:
- basic components of a circuit include power source, load/resistor (light bulbs, etc.), conductor and switch
- types of circuits include series, parallel, short circuits
- current flow in a circuit: alternating current (AC) and direct current (DC)
- voltage, current, and resistance are related: Ohm’s Law (V=IR)
- relative dangers of current and voltage
Note to students: This unit works best with hands on activities. We can try a few things at home for STATIC ELECTRICITY and use a PHET simulation to build virtual circuits.
TURN IN ASSIGNMENTS INCLUDE A PHET SIMULATION AND A TAKE HOME TEST THAT INVOLVES DRAWING CIRCUITS AND CALCULATING CURRENT. WORK, POWER, ENERGY will not be covered this year.
Jan 10: STATIC ELECTRICITY: CHAPTER 9 KNOW HOW OBJECTS GET CHARGED AND WHAT FACTORS AFFECT THIS.
TYPES OF CHARGE PPT NOTES
What is Static Electricity? Ted Ed video:
KNOW: objects get charged by transferring electrons. Like charges repel, opposite charges attract, and charged objects can attract neutral ones.
BE ABLE TO: Predict which objects would repel, attract, or do nothing, given the charge of each.
Suggested HW: Read pages 274-277, Answer CYU p 278 #1,2,4,7-9,11, 13
HW: At home activity
KNOW: Some objects are better at holding a charge than others. Some materials more readily allow electrons to pass through them than others.
BE ABLE TO: Describe the electrostatic series, list some examples of insulators and conductors. Describe what will be the overall charge if two objects rubbed together.
If we were in class we would have done a lab on this.
CHARGING OBJECTS PPT NOTES,
Intro Bozeman Video, 8 min: How an electroscope works
KNOW: that objects can be charged by friction, conduction and induction.
BE ABLE TO: Describe which way the leaves of an electroscope will move when an object with a given charge is brought near or touched. Describe what happens to the charges when you touch it with a finger. Describe the purpose of grounding, Faraday cages, lightning rods.
Suggested HW: Electroscope WS, This reads as a story, one scenario leading to the next. Identify what charges are where with each scenario continuing from the previous.
Suggested HW: Read pages 281-283, Answer CYU p284 #2, 4, 5, 7, 8, 9
Charging by induction video
Electrostatic Force PPT NOTES
WATCH INTRO video: How a van de Graaf Generator works
WATCH: Video of Van De Graaf demos
KNOW: What electrostatic force means and what factors determine it.
BE ABLE TO: Describe some uses of static electricity (end of chapter 9). Explain why objects react the way they do when in contact with a Van de Graaf generator.
Suggested HW; Read pages 285-286, Answer CYU p287 #1, 2, 3, 9
If in class we would actually have a big Van de Graaf generator to play with.
April 27-May 22: CURRENT ELECTRICITY, chapter 10
PARTS OF A CIRCUIT PPT NOTES
KNOW: parts of a circuit, what is needed for current to flow. Know the difference between series and parallel circuits.
BE ABLE TO: Draw a circuit diagram using correct symbols from a word description.
SUGGESTED HW: Circuit Symbols and Diagrams WS
CELL AND BATTERY PPT NOTES
KNOW: Difference between a battery and cell, what types of cells and their uses, parts of a cell. Could other solutions be used as an electrolyte? If so, what?
SUGGESTED HW: CYU p305 #1-8, Battery labelling WS
More info Link: how batteries (cells) work
If we were in class there would be a lab on batteries.
MEASURING CURRENT PPT NOTES
KNOW: Definition of current. Circuit diagram symbol for instrument that measures current and how it is placed in the circuit (in series or parallel?). How is current affected in series vs parallel circuits.
BE ABLE TO: Read ammeter (don't forget units). Calculate current, given a word problem
SUGGESTED HW: Current WS p174-175
VOLTAGE PPT NOTES
KNOW: Definition of voltage. Circuit diagram symbol for instrument that measures voltage and how it is placed in the circuit (in series or parallel?). How is voltage affected in series vs parallel circuits.
BE ABLE TO: Read volt meter (don't forget units).
SUGGESTED HW: Voltmeter WS,
***ASSIGNMENT TO BE TURNED IN: PHET Simulation Due May 15
Ohm's Law PPT NOTES:
KNOW: define ohm's law, resistance. Why we use resistors.
BE ABLE TO: calculate voltage, current, resistance given a word problem.
SUGGESTED HW: Ohm's Law WS
STILL CURIOUS? READ TEXTBOOK ON WORK, POWER, ENERGY
TAKE HOME ELECTRICITY TEST STUDY GUIDE (STATIC AND CURRENT)
Here are some PRACTICE QUESTIONS
MAY 22****PLEASE SEE TEAMS FOR Take Home UNIT TEST: Will be posted for a limited time on May 22 and is to be submitted May 22 No lates. ****
Start Ecology, Go to Earth Science Tab
LINKS FOR MORE INFO:
Sparkfun explains electricity basics
more info on Electrostatics
Charging by Contact and Induction
PHET Simulation: John Travoltage
9 tricks with Static Electricity
Charging by induction explained
Bozeman charging electroscope
In depth description of Van de Graaf Generator
How to make a lemon battery
Sci Show Explains the Lemon Battery
How to use a Bread Board 12 min
Collaborate and Research your Mud Battery. Discuss what you will need, who will bring what, where and how to assemble.
Keep in mind that the bacteria in the dirt is integral to the functioning of your battery.
Task 1 is due May 10:
- Provide a testable hypothesis for each variable the predicts what will happen to the voltage if the variable were changed.
- Provide a list specifying the materials that will be used to construct the your first mud battery. Include measurements.
- Write a 1 page report explaining the advantages of the features you’ve included in your design.
- Mud battery: Discuss what you each have researched, what variable you will manipulate and why, what design you will use, compile your data and decide who will submit for the group. ONE SUBMISSION PER GROUP. Each submission should have group members in subject line. Task 1 to be emailed no later than Friday, May 10. check the criteria on the link to make sure you have everything.