1. Electric Current & Electrical Energy http://www. brainpop

2. Electric Current (I) A flow of charges
The rate at which charges pass a given point
Similar to frequency of a wave
Unit of measurement is Amperes (A)

3. Amperes
The number of charges passing a point per second.

4. Making Charges Move
An electric field inside the wire causes the free electrons in the wire to move.

5. Direct & Alternating Current (use Holt-online book pages 13 Additional Resources Visual Concepts)DC
Electrons flow in one direction (battery in a flashlight) AC
Electrons move in 2 directions (plug for the tv)

6. Voltage (Potential Difference) (use Holt-online book pages 14 Additional Resources Visual Concepts)
A measure of how much work (F x d) is needed to move a charge.
The potential difference between points in a circuit.
Unit of measurement is Volts
The amount of energy (work is a transfer of energy) released as a charge moves between two points in the path of a current.

7. Resistance Opposition to the flow of electric charge.
Expressed in ohms
Electrical friction
Resistance depends of the material and temperature of the object.
Conductors vs. Insulators
Hot vs. Cold

8. Resistance

9. Generating Electrical Energy
Cell
A device that produces an electric current by converting chemical or radiant energy into electrical energy.

10. Cell
Parts of the cell
Electrolyte (mixture of chemicals that allow charges to flow)
Electrode ( part of a cell through which charges enter or exit)
Chemical changes between the electrolyte and the electrodes convert chemical energy into electrical energy.
Types of cells
Wet
Dry

11. Batteries are cells

12. Thermocouples
A device that converts thermal energy into electrical energy
Usually do not generate much energy

13. Photocells A device that converts light energy into electrical energy
Most are made of silicon atoms
When light shines on the panel, electrons gain energy to move between atoms; then the electrons are able to move through the wire to provide electrical energy.

14. Summary questions
What is the unit of measurement for electric current?
What are 2 kinds of electric current?
What is the unit of measurement for voltage?
What are 2 kinds of cells?
What device converts light energy into electrical energy?