1. ELECTRICITY Part 1: Electrostatics.

2. ► One of the three basic energy use sectors.

3. Electricity Generation by Source 67% Fossil Fuel

4. Electricity Generation by Source 77.5% Fossil Fuel

5. Electric Power Generation 1950-2005

6. Electrostatics ► Study of charges that are NOT moving. ► What is Charge? ► A new property of matter. Similar to mass. ► Mass creates and responds to gravitational fields ► Charges create and respond to electric fields.

7. ► There are two types of charges (Ben Franklin):  positive (+)  negative (-) ► Symbols for charge are q or Q ► Units of charge: Coulomb (C) ► A Coulomb is a lot of charge. Usually deal in micro coulombs and less in electrostatics. ► Fundamental charge: Magnitude of the charge on an electron or proton. ► e=1.602 x 10 -19 C ► Like charges repel, Unlike charges attract.

8. Definitions ► Conductor: Material that charges are free to move around in. Examples: metal (silver is best but copper is almost as good) ► Insulator (Dielectric): Material that charges are NOT free to move around in. Examples: glass, quartz, wood. ► Semiconductor: Can behave as either depending on conditions: Silicon, Germanium, Gallium- Arsenide.

9. Forces on Electric Charges ► Coulomb’s Law – for point charges and spherical charges

10. Electric Force ► In a hydrogen atom the proton and electron are separated by 5.3 x 10 -11 m ► What is the electric force between the proton and the electron?

11. Electric force strength A. 1.602 x 10 -19 N B. 8.2 x 10 -8 N C. 4.36 x 10 -18 N D. 5.13 x 10 11 N

12. Forces on Electric Charges ► Gravitational force on a mass: ► F = mg ► Electric force on a charge: ► F = qE ► E (electric field) = F/q is the force per unit charge that a given charge experiences. (vector) ► In general E is not constant in space and time.

13. ► If we move a charge in an electric field, we do work on it. ► W = Fd = (qE)d ► Define Voltage as V = Ed (uniform field) ► Note V = W/q (J/C): work done per unit charge in moving it through an electric field. ► V is potential energy per unit charge ► Equivalent to raising mass up in a gravitational field.

14. Work done by electricity ► What is the work done in moving a charge q = 1.602 x 10 -19 C through 120 V? ►

15. Work done in moving charge A. 120 J B. 1.602 x 10 -19 J C. 1.92 x 10 -17 J D. 240 J

16. UNITS OF E & V ► V = PE/q (Joule/Coulomb = Volt) ► E = F/q (Newton/Coulomb) OR OR ► E = V/d (Volt/meter)

17. CAPACITOR ► Device for storing charge ► Two conductors separated by an insulator. ► Battery moves charge from one plate to another.