1. Bell Ringer: 3.1A Data Sheet You have fifteen minutes in your groups to COMPLETE the data.

2. Notes on Electrical Flow Rate

3. Electrical Rate: Page 82 Electrical Current = Charge moved time interval I =  q  t Flow of electrons! This is a measure of the amount of charge that flows through a cross section of a conductor per unit of time

4. Why can a bird sit on the power line? When does the current flow? If there are voltage or potential difference, then the current starts to flow from high voltage to low voltage. But when a small bird sits on the power line, both feet are on the same voltage line! Therefore, there are no potential difference between these two feet. D o N o t C o p y

5. Why can a bird sit on the power line? Let's say the power line is very low, almost touching the ground, and a chicken is trying to cross it. If one leg is on the ground and the other one is on the power line, then there are potential difference between these two legs. Therefore, there is a flow of charge and eventually the chicken will be barbequed like the diagram above. D o N o t C o p y

6. Frequency (continue on 82) Frequency = Number of cycles time interval How often something repeats itself! f = 1 T T = Period, the time it takes for one complete cycle. T = 1 f And

7. Quick Tips (continue on 82) Ammeters measure current. Ammeters are connected in series. Voltmeters measure voltage. Voltmeters are connected in parallel.

8. Mini Lab: Rate of Current (pg 81) Question: Where is the rate of charge flow within a simple circuit the greatest? The least? Or is it the same everywhere? Purpose: To determine location within a simple circuit where the rate of charge flows is the greatest. Materials: Compass, two D-cells, light bulbs, leads.

9. Reflection: Rate of Current Page 81 Discussion: (top half of page) Where was there the least amount of current? How can you tell? What factors contributed to that solution? What did you learn? Sketch: (Bottom half of page) Make a colored sketch where you label all of the parts.