1. Current

2. Current (I) Flow of charge Amount of charge that moves past a specified point per second I = Q/t Units C/s = Ampere (amp)

3. Relationship Between I and V Electrons flow from one place to another due to the difference in potential (V) In general, the greater the potential difference (V), the greater the electric current Properties of the conductor also affect the amount of current

4. Direction of Current Flow Electrons flow from (-) to (+) terminals Conventional Current –Before electrons were discovered, it was believed that charge was + and that it flowed from + to – –Still shown this way in many schematic diagrams of electricians

5. Ammeter Measures current Electrons enter through the – terminal and leave through the + terminal

7. Examples Calculate the current through a toaster if it takes 900C to toast two slices of bread in 1.5 min. A light bulb with current of.80A is burning for 20 min. How much charge has passed through the filament of the bulb? How many electrons is this?

8. An electroscope with an excess of 1.25x10 10 electrons discharges in.50sec. What is the current through the ground wire? A toaster uses a current of 10A for 125sec to make toast, while giving off 1.5x10 5 J of heat. What is the “voltage”?