1. Electromagnetics for 8th grade
Activity Under Development
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Electromagnetics for 8th grade
Based upon NASA’s “The Case of the Technical Knockout”
Current Detective
Electrifying Electricity

2. Activity Guide Challenge: Discuss (5-10 minutes)
Generate Ideas and Multiple Perspectives (instructor choice)
Research and Revise (and Test Your Mettle)
Activity 1: Review the relationship between electricity and magnets (5-10 minutes)
Activity 2: Copper coil motor (10 minutes) – this can be conducted as a demonstration or each group can construct a copper coil motor
Activity 3: Create a Current Detector (15-20 minutes)
Activity 4: Create an Electromagnet (15-20 minutes)
Activity 5: Complete Data Chart (10-15 minutes)
Go Public: Revisit challenge (instructor choice)

3. Teacher Tips
The magnetic motor can be a demonstration/review or a hands-on activity for your students.
You may need to use the needle nose pliers to straighten the ends of the copper coils used in the magnet motor. BE CAREFUL not to bend the coil.
The current detector shows dramatic response when testing the battery and much less dramatic response with the electromagnet. It does show a response, though!
These experiments show the relationship between electricity and magnets.
A magnet that is moved past a copper coil causes the electrons to move, moving electrons create electricity.
This activity is designed for 6 groups of 4 students each.
Each group of students will do the same activities.
You will prepare a bin of materials for each of the 6 groups.

4. Teacher Prep Assemble materials from next page
Set up 6 bins of the same materials for 3-4 students at each of 6 tables
4 D-cell batteries
4 D-cell battery holders
2 pieces of 3 meter copper wire with insulation stripped off ends (they are coiled on cardboard)
1 piece of ½” diameter PVC tube
2 jumper cables
1 compass
1 roll clear tape
1 bar magnet
1 12 cm iron nail
1 plastic bowl
1 box of 100 paper clips
1 Electromagnetic chart
2 safety pins
1 copper wire coil
1 metric ruler
Set up 6 stations, 1 at each table.

5. Materials 6 PVC pipes ½-inch diameter x 4-inches long
24 D-cell batteries
24 D-cell battery holders
6 copper coils (with ends stripped)
12, 3-meter piece of gauge insulated wire with ends stripped off
12 large safety pins
6 pens/pencils
12 jumper cables
6 metric rulers
6 compasses
6 rolls clear tape
6 bar magnets-plain
6 bar magnets with North and South Poles marked
6 12 cm iron nail
6 plastic soup bowls
6 boxes of 100 paper clips
6 copies of Electromagnet Data Chart – stored in mechanical room filing drawer on bottom left

6. Location of All Materials
Drawer 4a1:
4 boxes labeled bar magnets
9 ½” diameter PVC tubes
10 6” iron nails
8 bags of 100 paper clips
28 mechanical pencils
9 compasses
Drawer 4a2:
12 rolls clear tape
7 ceramic bar magnets
16 jumper cables
Drawer 4a3:
20 D cell batteries
6 sets of insulated copper wire (2 4-meter
lengths rolled on cardboard)
8 rulers
36 D-cell batteries
1 plastic box containing 8 copper coils,
16 safety pins, 8 rubber bands, 1 pair needle nose pliers
Drawer 4a4:
8 plastic bowls

7. Worksheet

8. Challenge
The president of a local office supply company, STEMco, has asked your class to design and build an executive desk toy.
The toy must be capable of some type of motion OR light up, but cannot contain batteries or be connected to an electric outlet.
The president’s son owns a magnet factory, so the toy MUST contain at least one magnet.

9. Guiding Question How are electricity and magnetism related? Review –
How can we detect electric current with a magnet, compass, and battery?
How can we create an electromagnet?
What can you do with a simple motor?
Review –
What is electricity?
What is an electromagnet?
Electricity is the flow of electrons across a wire. An electromagnet is a device made when electric current travels through a wire coil. (Definition from Hartcourt Brace science glossary).

10. Activity 1: How are electricity and magnets related? (5-10 minutes)
A magnet can induce an electric current when moved through a coil of copper wire.
A magnet that is moved past a copper coil causes the electrons to move.
Electricity is the flow (movement) of electrons.
A magnet can also reverse the flow of electrons (electricity) in a copper wire.

11. Activity 2: Create Copper Coil Motor (10 minutes)
Materials needed:
1 D cell battery
1 coil of copper wire
1 bar magnet
2 safety pins
1 rubber band
The teacher can conduct this part of the activity as a demonstration for review or engagement!

12. Attach doubled rubber band to battery.

13. At each end of battery, insert one safety pin in between rubber band and battery.
Make sure both safety pins are level at the top.

14. Put a magnet under the battery - in line with the long axis of the battery.

15. Insert copper coil in the small loops at the top of each safety pin.
You may need to use the needle nose pliers to straighten the ends of the copper coil. BE CAREFUL not to bend the coil.

16. Very lightly spin the coil. What happened. Now reverse the magnet
Very lightly spin the coil. What happened? Now reverse the magnet. What happened?
The copper coil should spin clockwise or counterclockwise the first time. When the magnet is reversed, the direction of spin of the wire will reverse!

17. Take Apart Copper Coil Motor
Take apart the coil motor.
Remove magnet from battery.
Remove copper coil from safety pins.
Remove safety pins
Remove rubber band.
Return materials to your bin.

18. Activity 3: Creating a Current Detector (15-20 minutes)
Materials for each group of 4 students:
2 jumper cables
2 pieces 18 gauge wire meters long (with ends stripped)
Small compass
D-cell battery
D-cell battery holder
Strong magnet
4 inch piece of ½-inch diameter PVC pipe
Clear tape

19. Wrap 3-m wire around compass
Wrap loops tightly around middle of compass:
Leave 40 cm at the end.
Wrap from North to South. The wire must stay at the middle of the compass
TIP: you may want to tape the wire on the compass to hold it in place as you wrap.

20. Placed D-cell battery in battery holder.

21. Line up the compass on your desk
Make sure North points North and lines up with the wire loops.
This is your current detector!

22. Connect one end of wire to the D-cell
Connect the compass to the D-cell battery using jumper cable. One end of the jumper cable on the compass wire, one end on the battery.

23. Touch other end of wire to D-cell
Connect a 2nd jumper cable to the battery terminal.
Touch the free alligator clip to the bare end of the wire.
Observe what happens and record your observations in your Electromagnet chart.
Disconnect the jumper cables from the battery and compass.

24. Wrap 3-m wire around PVC tube
Leave at least 50 cm of wire at each end.
Wrap tightly but DO NOT overlap the wires.
TIP: you may need tape to hold the wire in place as you wrap.

25. Connect one wire on current detector
Use a jumper cable to connect one wire on the current detector to one wire on the PVC tube.
Use a second jumper cable to connect the other wire on the current detector to the free wire on the PVC tube.
It is very important that the cardboard tube is as far away from the compass as is possible!!!

26. SLOWLY insert a magnet labeled with North and South into the PVC tube and pull out. Insert and pull out.
Observe and record what happens to the compass needle.
The compass must be FLAT to work. You may need to hold it in place.
Note: South is inserted into the tube in the image below.
The compass needle should move one way or the other away from North.

27. Predict ….
What will happen to the compass needle if you reverse the magnet before you insert it into the tube, North first?
Now test your prediction. Remember the compass must be FLAT to work.
Note: North is inserted into the tube
Disconnect all wires and straighten wire that was wrapped around PVC. Wrap it around cardboard and return materials to your bin.
The compass needle will move opposite the direction it moved when South was inserted in the tube.

28. Conclusions – for your worksheet
Describe what happened to the compass when current ran through the wire.
Describe what happened when you reversed the position of the bar magnet in the tube.
In what way is the compass needle’s movement evidence of a current in the wire?
What do you think produced a current in the wire?
The compass moved when current ran through the wire.
The compass needle swings one why when the magnet is inserted and it swings the other way when it is pulled out. When you reverse the magnet, you cause the compass needle to swing in the opposite direction from how it originally swung.
When you moved the bar magnet into the coil of wire (tube), it induced a weak electric current in the coil. A compass is sensitive to electric current. When a compass detects an electric current, it moves.
The movement of the magnet through the coil produces the current. Faraday observed that whenever a coil is in the presence of a changing magnetic field, it causes a current in the coil. The magnet causes electrons to flow – the flow of electrons is electricity.

29. Activity 4 - Create an Electromagnet (15-20 minutes)
Materials per group of 4 students:
4 D-cell batteries
4 D-cell battery holders
Large iron nail (16 cm)
100 metal paper clips in a plastic bag
Small plastic container
2 jumper cables
3 meters of 24 gauge copper wire with ends stripped off
Electromagnet Chart

30. Wrap wire around nail
Leave approximately 25 centimeters of wire free at each end.
Wrap the wire around the nail tightly, making your coils as close together as possible. Do NOT overlap the wire!!!
Stop at the end of the nail. (You may have more than 25 centimeters of wire left at that end.)

31. Insert batteries in battery holders
Make sure – end of battery is at – end of battery holder.

32. Connect wire to battery
Use a jumper cable to attach one end of the wire to one end of the battery.
Connect another jumper cable to the free end of the battery and the free end of the wire.
This is an electromagnet.

33. Test your electromagnet
Place one end of the electromagnet in a bowl full of paper clips.
Count the number of paper clips and record in your Electromagnet Data Chart.
Repeat this test 2 more times.
Record in Electromagnet Data Chart. Calculate average # of paper clips picked up.
Disconnect one end jumper cable from the battery.

34. Add 2nd battery
Clip another battery in series onto your electromagnet.
Re-test it and record the number of paper clips you can pick up.
Repeat this test for a total of 3 trials.
Record in Electromagnet Data Chart. Calculate average # of paper clips picked up.
Disconnect one jumper cable from battery.

35. Add 3rd battery
Clip a third battery in series onto your electromagnet.
Re-test it and record the number of paper clips you can pick up.
Repeat two more times for a total of 3 trials.
Record in Electromagnet Data Chart. Calculate average # of paper clips picked up.
Disconnect one jumper cable from battery.

36. Add 4th battery
Clip a fourth battery in series onto your electromagnet.
Re-test it and record the number of paper clips you can pick up.
Repeat two more times for a total of 3 trials.
Record in
Electromagnet Data
Chart. Calculate
average # of paper
clips picked up.
Disconnect one
jumper cable from
battery.

37. Activity 5: Complete data chart (10-15 minutes)
Calculate the average number of paper clips picked up for each total battery voltage and record in Electromagnets Data Chart.
Graph your results.
What happened to the electromagnets strength when you added more volts?
The electromagnet should get stronger each time you add another battery (adding volts). This activity could be done in the classroom after visiting the STEMmobile.

38. Go Public: Revisit the Challenge
The president of a local office supply company, STEMco, has asked your class to design and build an executive desk toy.
The toy must be capable of some type of motion OR light up, but cannot contain batteries or be connected to an electric outlet.
The president’s son owns a magnet factory, so the toy MUST contain at least one magnet.

39. Vocabulary
Electromagnet - An arrangement of wire wrapped around a core producing a temporary magnet
Electricity – the low of electrons
Induce – cause to happen
Magnet – object that attracts certain metals (especially those containing iron)
Maglev – magnetic levitating system.
A transportation device that relies on electromagnets to propel it.
Repulsion and attraction work to push and pull the train along.