1. Aim: How do we explain electric potential difference (or Voltage)?

2. Do Now
Find the work done in joules in moving 5 electrons through a potential difference of 6.0 V. V=W/q q=5 (1.6 x C)=8 x C W=Vq= (6V)(8 x C)=4.8 x J

3. Electric Current Electric current is the flow of charge
The flow of positive charge is called conventional current.
The flow of negative charge is called electron current.

4. The cause of current
Current will flow between two points whenever a potential difference is maintained.

5. Electric Current
I = q/t I = current (measured in amperes) q= charge (measured in coulombs) t= time (measured in seconds)

6. Electric Current Problems
1. A current of one ampere is a flow of charge at the rate of ____1___ coulomb per second. (
2. When a charge of 8 C flows past any point in a wire in 2 seconds, the current is ___4_____ A.
3. If 5 C of charge flow past a point in 10 seconds, then the current is ____0.5_____ A.
4. If the current at a point is 2.0 A, then ___20____ C of charge flow past this point in 10 seconds.
5. If 4 A of current flow past point A for 3 seconds, how many electrons passed point A?______12 C=7.5 x 1019 electrons____

7. Drift Speed vs Current
Drift speed refers to the average distance traveled by a charge carrier per unit of time
Current is the amount of charges that pass a given point per second

8. Electric Current Problems
6. The diagram at the right depicts a conducting wire. Two cross-sectional areas are located 50 cm apart. Every 2.0 seconds, 10 C of charge flow through each of these areas. The current in this wire is ____ A.
a b c d. 1.0
e f. 20 g. 10 h. 40
none of these

9. Electric Current Problem 7
If 12 C of charge flow past point A in 3 seconds, then 8 C of charge will flow past point E in ___2_____ seconds. True or False: The current at point E is considerably less than the current at point A since charge is being used up in the light bulbs. FALSE

10. Electric Circuit
A path for current to flow.