1. Electricity on the Move

2. Current Electricity Unlike static electricity, which does not move except when discharged, current electricity is a continuous flow of electric charge. An example of this is a battery. When we hook something up to a battery, the electrical current flows through a path called a circuit.

3. Current Electricity: http://www.brainpop.com/science/energy/c urrentelectricity/preview.weml http://www.brainpop.com/science/energy/c urrentelectricity/preview.weml

4. Lighting a Light Bulb In order for a light bulb to light there must be a closed path to connect all of its components. This closed path is called a circuit.

5. Circuit Measurements Electric Current - Flow of electrons through a material. Measured as the amount of current that passes a conducting wire every second. Measured as the amount of current that passes a conducting wire every second. Electrical Potential – Stored electric energy Stored electric energy

6. Circuit Measurements When given the opportunity, objects will move from higher potential energy to an area of lower potential energy When given the opportunity, objects will move from higher potential energy to an area of lower potential energy Electrical potential is related to their electrical fields and not to height – as electrons build up on one side they “want” to flow to an area w/ less potential Electrical potential is related to their electrical fields and not to height – as electrons build up on one side they “want” to flow to an area w/ less potential

7. Circuits A path that allows an electric current to flow We can use a circuit diagram to show the path of the electric current. Copy symbols on page 353 and place by each name on the next two slides

8. Understanding the Symbols Conducting wire allows electricity to flow easily The cell is an energy source. A battery is a combination of cells. A lamp is a source of light

9. Understanding Symbols (con’t) A switch will allow you to turn the electricity on or off without moving any components of the circuit. A resistor is used to represent any one of the many components (loads) that convert electrical energy to other forms of energy. This resists the movement of charge through a circuit

10. Moving Charges The symbol for current is I and the symbol for charge is Q, t is used to represent time. Current = charge moving past a point time I = Q t

11. Charge (Q) is measured in Coulombs (C) Current (I) is measured in Amperes (A) Time (t) is measured in seconds (s)

12. Answer the following Questions 1.How is static and current electricity different? 2.Give a real life example of one way that you have used static electricity and current electricity? 3.What is it called when current electricity flows through a path? 4.If 320 C of charge pass a point in a conductor in 7 min, what is the current through the point in the conductor? (Don’t forget the units!)

13. Voltage Voltage – causes current to flow through an electrical circuit Volt – unit of measure to measure this potential A Voltage Source (battery or generator) is required to maintain the electrical potential in a circuit.

14. Electrical Current Water flowing thru a pipe depends on more than the angle of the pipe. It also depends on the length of the pipe, diameter of the pipe and if the pipe is clogged or open. Electrical Current is measured in Amperes Amount of Electrical Current ( amps) depends on more than just Voltage, it depends on the Resistance found in the circuit.

15. Electrical Resistance the opposition to the flow of electricity – measured in Ohms – symbol is the Greek letter Omega - Water flowing thru a pipe depends on more than the angle of the pipe. It also depends on the length of the pipe, diameter of the pipe and if the pipe is clogged or open. Electricity will take the path of least resistance The greater the resistance, the less current there is for a given voltage. a. Longer wires have greater resistance than short wires a. Longer wires have greater resistance than short wires b. Thin wires have more resistance than thick wire b. Thin wires have more resistance than thick wire c. High conductors have less resistance than insulators c. High conductors have less resistance than insulators