1. Electric Current
6.2

2. Electric Current
- is the net movement of electric charges in a single direction through a wire or conductor.
Measured in amperes - I

3. Voltage Difference Force that causes electric charges to flow
Charges flow from high voltage to low voltage
The “push” that causes e- to move from - to +
Measured in volts (V)

4. Circuit
- A closed path that electric current follows

5. A battery can provide the voltage difference that keeps electric current flowing.

6. Batteries
Dry – Cell Chemical reactions occur in a moist paste causing transfer of electrons.
Wet – Cell
Contains two connected plates made of different metals in conduction solution

7. Resistance – tendency for a material to oppose the flow of electrons charging electrical energy into thermal and light energy
Making wires thinner, longer, or hotter increases resistance.
All materials have some resistance.
Measured in ohms - Ω

8. Ohm’s Law - current in a circuit equals voltage divided by resistance

9. Set up problem and show work.
Solve for Current
The voltage difference in a graphing calculator is 6 V, and the resistance is 1,200 Ω. What is the current through the batteries of the graphing calculator?
What is given?
What is unknown?
Which formula?
Set up problem and show work.
Does your final answer have the correct unit?
Voltage difference = 6 V
Resistance = 1,200 Ω
Current (I) in A (amperes)
I = V R
I = V
1,200 Ω
I = V = A Ω

10. Resistance Equation The resistance is 240 Ω.
Suppose a current of 0.5 A flows in a 75-W lightbulb. The voltage difference between the ends of the filament is 120 V. Find the resistance of the filament.
The resistance is 240 Ω.

12. The voltage difference in a graphing calculator is 6 V, and the resistance is 1,200 Ω. What is the current through the batteries of the graphing calculator?