1. Electricity & Circuits
& for juniors: Electromagnetism

2. Know basic circuit symbols (notes)

3. Intro to Circuits activity
Do not directly connect the ends of a battery with wire… …without any resistance, too much electricity will flow and destroy battery, or worse.

4. Intro to Circuits activity
Build the following devices.
Once functional, draw circuit diagrams for each :
Source of electrical voltage (battery) + light + switch
Source of voltage + two slightly dimmer lights
Source of electrical voltage + two equally bright lights
Source of voltage + two switches controlling two separate lights.
Source of voltage + one switch, two conditions one bright light or two dim lights

5. Basic Learning Objectives
Correctly interpret & use circuit symbols.
Identify & know properties of light bulbs & resistors placed in series vs. parallel circuits.
Describe meaning of voltage, potential, voltage drop, current, amperage. Use water analogies.
Describe voltage drop across resistors.
Describe difference between DC and AC power.

6. Intermediate Learning Objectives
Calculate resistance of multiple resistors in series and in parallel, in correct units.
Predict circuit amperage using Ohm’s Law.
Describe how to use a voltmeter and ammeter correctly. (We will use combined multi-meters.)
Describe the purposes and function of fuses, circuit breakers and GFIs.

7. Advanced Learning Objectives
Describe how capacitors work, such as in parallel to a bulb on a circuit whose voltage can be turned on/off.
Draw a series of circuit diagrams using color-coding to show ‘pressure’ and electron ‘flow’ at different moments in time in circuits with capacitors.
Wire a house model with a variety of circuit types.
Describe the phenomenon of electromagnetism.
Describe how to build devices using electromagnetism: generator, motor, speaker, transformer. (Juniors only)

8. Have you read? Chapter 35 - Basic Learning Objectives
Chapter 34 - Intermediate LO’s
Chapters Advanced LO’s

9. Background on Electrical Current & Circuits
Go to this site:
Open Classroom Tutorial mode
Open Current Electricity chapter
Read through each lesson:
1) Potential 2) Current 3) Resistance 4) Circuits
Complete Q’s at bottom each lesson, check A’s

10. Points to discuss based on student Q’s
Indicated direction of current - Conventional vs. Electron Flow
Ben Franklin vs. modern understanding of electrical current
Battery polarity, resistor polarity, does current direction matter
Purpose of battery in circuit
How a battery works and why multiple lines in diagram (2 electrodes/cell)
Circuit continuity, open vs. closed
Equivalent ways to draw circuits – bends don’t matter, distance (mostly) doesn’t matter. How to show non-connected wires ‘jumping’ each other
Bulbs are resistors too
Series vs parallel; dealing with both in same circuit
How an incandescent screw-in bulb works

11. Points to discuss based on student Q’s
Water reservoir & gravity = analog for pressure or flow
How it relates to voltage (= potential), voltage drop, amperage (= current)
Electric field = electric potential; drawing arrows for effect on + test charge
Calculating resistance of series of resistors
Using Ohm’s Law to find current flow
Calculating resistance of resistors in parallel
Circuit w both?

12. QUIZ
See if you can answer questions on the following slides using prose & pictures.
Each slide matches an Electricity & Circuits learning objective .

13. Basic Learning Objectives
Correctly interpret & use circuit symbols.
Q: What are these circuit components?

14. Basic Learning Objectives
Identify & know properties of light bulbs & resistors placed in series vs. parallel circuits.
Q: Label these circuits as series or parallel.

15. Basic Learning Objectives
Describe meaning of voltage, potential, voltage drop, current, amperage. Use water analogies.
Q: Match the correct water analogy to concepts above.

16. Basic Learning Objectives
Describe voltage drop across resistors.
Q: Draw a circuit diagram to represent this water analogy.

17. Basic Learning Objectives
Describe difference between DC and AC power.
Q: Draw the corresponding voltage-over-time graph and for AC and the cartoon for DC.

18. Intermediate Learning Objectives
Calculate resistance of multiple resistors in series and in parallel, in correct units.
Q: Calculate the total resistance of each circuit:

19. Intermediate Learning Objectives
Predict circuit amperage using Ohm’s Law.
Q: Write Ohm’s Law in symbols and words.

20. Intermediate Learning Objectives
Predict circuit amperage using Ohm’s Law.
Q: Calculate the current in each circuit with correct units.

21. Intermediate Learning Objectives
Describe how to use a voltmeter and ammeter correctly. (We will use combined multi-meters.)
Q: In what mode is the multi-meter being used in each picture? What are the critical differences?

22. Intermediate Learning Objectives
Describe the purposes and mechanism of fuses, circuit breakers and GFIs.

23. Intermediate Learning Objectives
Describe purpose and mechanism of fuses, circuit breakers and GFIs.

24. Advanced Learning Objectives
Describe how capacitors work.

25. Advanced Learning Objectives
Explain the function of a capacitor placed in series or parallel with a lightbulb circuit that can be turned on/off.

26. Advanced Learning Objectives
Wire a house model with a variety of circuit types.

27. Advanced Learning Objectives
Describe the phenomenon of electromagnetism.
Right-Hand Rule

28. Advanced Learning Objectives
Describe how to build devices using electromagnetism: generator, motor, speaker, transformer. Describe how they operate.

29. House Wiring Project Must include these functioning elements:
Doorbell switch outside & doorbell inside door
Single hall light controllable from two switches: inside front door & by bedroom
Bathroom venting fan for mildew & odor control
Dining room light controlled by one switch with three settings: off, low light, bright light
Living room ‘live’ outlet for plugging in entertainment system
Bedroom light that turns on gradually, off>dim>bright so as not to blind dilated night eyes
Power distribution panel in the utility room, with connections to street lines, sending electricity to each room circuit
Functioning fuse for each room circuit on utility room distribution panel, with fuse adjusted for load in each (A+)

30. House Wiring Project
House floorplan on large board with rooms labeled: entrance hall, bathroom, kitchen/dining room, bedroom, living room, utility room
Wiring schematic or diagram on floorplan
All components installed through board, operable from front, wired in back

31. Electromagnetic Devices Project Juniors only
Successfully build:
World’s simplest electromagnetic generator
World’s simplest electrical motor
World’s simplest speaker that makes recognizable music
World’s simplest voltage step-up/step-down transformer
World’s simplest microphone

32. Electromagnetic Devices Project Juniors only
Evaluation criteria:
Successful, working device?
8 x 11 illustrated poster explaining clearly how it works?
Accurately explain it to group verbally?
Due by Th 6/18 at latest.
Can present whenever done: Th 6/11 (55 min), M 6/15 (55 min), Tu 6/16 (30 min), W 6/17 (2 hrs), Th 6/18 (30 min) = 4 hrs 50 min total