2. ELECTRICITY

3. l The purpose of an X-ray unit is to convert electric energy into: l ELECTROMAGNETIC ENERGY of the x-ray beam

4. TYPES OF ELECTRIC ENERGY CONVERSION l Recharging a car battery converts electric energy into chemical energy l table saw converts into mechanical energy l Kitchen appliances converts to thermal energy

5. ELECTROSTATICS l Matter has: l mass l form l energy l (may also have:)electric charge l ELECTRIC CHARGE l Positive and negative l Electron and Proton

6. ELECTRON AND PROTON l Electrons can travel from outer shell of one atom to another easily l Protons cannot travel easily or at all because they are fixed in the nucleus l

7. THEREFORE: ELECTRIC CHARGE IS PRIMARILY ASSOCIATED WITH ELECTRONS

8. ELECTROSTATICS l The study of electric charges in stationary form. l Static electricity!!!

9. ELECTRIFICATION ELECTRIFIED!!! l An object which as too many or two few electrons is considered to be electrified. l “The transfer of electrons from one object to another causes the first object to be positively electrified and the second object to be negatively electrified” page 76

10. CAUSES OF ELECTRIFICATION l Contact l Friction l Induction l Person to object l Balloon l Lightning

11. GROUND l Electrically neutral object which acts as a reservoir for electric charges l

12. COULOMB (C) l Because the charge of an electron is too small to measure, a fundamental measuring unit for electric charge is 1 C or l 6.3 x 10 to the eighteenth power electron charges

13. ELECTROSTATIC LAWS l Like charges repel l unlike charges attract l Both form an electric field l Positive field radiates outward l Negative field radiate inward

14. ELECTOSTATIC FORCE IS THE REPULSION OR ATTRACTION BETWEEN CHARGES DUE TO THE ELECTRIC FIELD

15. COULOMB’S LAW: THE GREATER THE ELECTROSTATIC CHARGES FOR EITHER OBJECT, THE GREATER THE ELECTROSATIC FORCE

16. COULOMB’S LAW: THE FORCE IS STRONGER WHEN OBJECTS ARE CLOSER, WEAKER WITH THE INCREASE OF DISTANCE

17. ELECTRIC CHARGE DISTRIBUTION l ELECTRIC CHARGES ARE UNIFORMLY DISTRIBUTED THROUGHOUT THE OBJECT OR ON ITS SURFACE

18. ELECTRIC CHARGE CONCENTRATION l THE ELECTRIC CHARGE OF A CONDUCTOR IS CONCENTRATED ALONG THE SHARPEST CURVATURE OF ITS SURFACE.

19. ELECTRODYNAMICS WHAT IS IT? l Study of Charges in Motion l AKA: Electricity!!!!!!

20. l FLOW OF ELECTRONS=ELECTRIC CURRENT l THE FLOW THE ELECTRONS IS OPPOSITE THE CURRENT l ELECTRONS FLOW EASILY THROUGH CONDUCTORS

21. l Insulators impede the flow of electrons. l Semiconductors do both!! l Superconductivity: some material display no resistance below a critical temperature

22. Four States of Electrical Matter l Superconductor l Conductor l Semiconductor l Insulator

23. Electric Circuits l Electrons flow along outer surface of wire. When the path is closed and resistance can be controlled, this is known as an electric circuit.