1. 4.2.1 Electrical Current Electricity Comes Alive

2. Definitions current: RATE OF CHARGE FLOW unit: C/s or AMPERE requires: POTENTIAL DIFFERENCE PATH FOR FLOW

3. 100 coulombs of charge pass through point A in 4.0 seconds. –What is the rate of current flow through point A? Example #1 I = Δq / t I = 100 C / (4.00 s) I = 25 A A

4. During a thunderstorm a lightning strike transfers 15.0 coulombs of charge in 10.0 milliseconds. –What was the electrical current produced in the strike? Example #2 I = Δq / t I = 15.0 C / (10 x 10 -3 s) I = 1.5 x 10 5 A

5. A wire carries a current of 50 amperes. –How much charge flows through the wire in 10 seconds? –How many electrons pass through the wire in 10 seconds? Example #3 I = Δq / t 50 A = q / (10 s) q = 500 C 3.125 x 10 21 e

6. End of 4.2.1 - PRACTICE