The Physics of Electricity and Magnetism

1. The Physics of Electricity and Magnetism Activity: Being a Part of a Current Event 9-12 Science Std: Phys 5h, 5j

2. In this activity we will be: 1. Seeing how a moving magnetic field induces (makes) an electric potential 2. Measuring how much voltage and current can be made 3. Comparing our generator with a known power source

3. So here we go Pick up the equipment you will need to do the activity from the side counter Verify you have all of the items listed here

4. How to use the Multimeter 1. Look at the dial of the multimeter You will see 2 symbols that you will be using: A V And And Current (A for Amps) These stand for: Voltage (V for volts)

5. How to use the Multimeter 2. Turn the dial to the 20 position under on the voltage side Take the red test lead on the multimeter and touch it to the positive (+) terminal on the battery Take the black test lead on the multimeter and touch it to the negative (-) terminal on the battery You should read about 1.5 volts

6. Start Your set up: 1. Clear off the table and put the “test tube generator” in the center of the table 2. Connect the red wire leads to copper wire on the generator – one wire on each end

7. Start taking readings 3. Take your ammeter and loosen black and red terminal screws on the front 4. Attach the red wires on the test tube generator to the 2 terminals on the ammeter 5. Take the bar magnet and slowly put it inside the test tube See if there is any movement on the ammeter – if not raise your hand

8. Start taking readings 6. Move the magnet in and out of the test tube to try to get the biggest current reading you can 7. When you get the biggest current reading you can, write down the maximum current We will use this number later

9. Start taking readings 8. Disconnect the test tube generator from the ammeter and connect it to the two test leads on the multimeter 9. Turn the dial on the multimeter to “m 200” under the voltage side The numbers you will see are in milivolts (or 1/1000 of 1 volt)

10. Start taking readings 10. Move the magnet in and out of the test tube to try to get the biggest voltage reading you can 11. When you get the biggest voltage reading you can, write down the maximum current We will use this number later

11. Don’t forget to put your names on your report Analyze your readings Question and Answer Report 1. Compare the current you made with the generator: Take the number of amps your cell phone battery can put out and divide it by the maximum amp reading you got from your generator then multiply that number by 1000 to adjust for the units Example: (950 mAh / 100 μA)(1000) This is the number of test tube generators that you would need to use to make the same amount of current that your battery can produce Record your calculations and answer on your report

12. Don’t forget to put your names on your report Analyze your readings Question and Answer Report 2. Compare the voltage you made with the generator: Take the voltage your cell phone battery can put out and divide it by the maximum voltage reading you got from your generator then multiply by 1000 to adjust the units Example: (3.7 V / 30 mV)(1000) This is the number of test tube generators that you would need to use to make the same amount of voltage that your battery can produce Record your calculations and answer on your report

13. Don’t forget to put your names on your report Analyze your readings Question and Answer Report 3. Answer the following questions: a. While you moved the magnet in and out of the test tube, did the values change or were they constant? b. What factors affect how big your readings are? In this experiment, what factors could you change? c. If you could change something in this experiment to make a generator that could power your cell phone, what would you change?

14. End of Activity Clean-Up In the last 5 minutes of class: Put all of your materials back on the side counter Clean up your table work area Turn in your report for this activity Don’t forget to put your team member’s names and the period # at the top of the sheet.

15. Questions?