1. Electricity and Magnetism Test Review

2. Static Electricity Def: Electricity created by a group of electrons staying together in one place. Electrons

3. Electric Charge How can an object collect electrons to get an electric charge?

4. Electric Charge How can an object collect electrons to get an electric charge? FRICTION!! - - - - - - - -

5. Types of Electron Buckets What are buckets called where electrons stay put when they are placed inside?

6. Types of Electron Buckets What are buckets called where electrons stay put when they are placed inside? INSULATORS: Rubber Plastic

7. Types of Electron Buckets What are buckets where electrons are free to move around in?

8. Types of Electron Buckets What are buckets where electrons are free to move around in? CONDUCTORS: Metal Water

9. Types of Electron Buckets What is it called when a conductor is connected to the GROUND?

10. Types of Electron Buckets What is it called when a conductor is connected to the GROUND? GROUNDING!

11. Multiple Charged Objects Imagine two objects, one with +10C of charge and the other one neutral. +10C No Charge

12. Multiple Charged Objects They are brought together and touch. Then are separated… +10C No Charge

13. Multiple Charged Objects What charge does each object have now? ???

14. Multiple Charged Objects The total initial charge was split between the two objects. +5C

15. Multiple Charged Objects Complete the practice problem on you review sheet. ???

16. Total Charge Imagine two neutral objects. Then several electrons are sent form one to the other. What is the TOTAL charge of the WHOLE system? 1)2) Electrons Neutral - +

17. Total Charge TOTAL # of electrons and protons between both objects stays the same, so the TOTAL CHARGE on the SYSTEM stays the same. (Even though balloon is – and face is +) 1)2) Electrons Neutral - +

18. Charge Interaction Imagine a charged balloon and a pith ball…

19. Charge Interaction What happens to the pith ball if the balloon is NEGATIVELY charged? -q

20. Charge Interaction The ball is attracted to the balloon -q

21. Charge Interaction What happens to the pith ball if the balloon is POSITIVELY charged? +q

22. Charge Interaction The ball is STILL attracted to the balloon +q

23. Charge Interaction What happens if the pith ball AND the balloon are both NEGATIVELY charged? -q

24. Charge Interaction The pith ball moves AWAY from the balloon. -q

25. Electric Fields Consider the electric field map below. Recall: WWPD A B

26. Electric Fields What is the charge on A and the charge on B? A B

27. Electric Fields What is the charge on A and the charge on B? A + B -

28. Coulomb’s Law Coulomb’s Law gives the force between two charged objects. Be careful of units and scientific notation when working problems.

29. Coulomb’s Law Coulomb’s Constant: q 1 and q 2 : charge on two objects d: distance between the two objects

30. Coulomb’s Law One hot air balloon flies through a thundercloud and comes out with a charge of -1000C. Another balloon below has a positive charge of +900C of charge. If they are separated by a distance of 200m, what is the electrostatic force between the two balloons?

31. Coulomb’s Law Inverse square Law: What happens if you double, triple, etc the distance??

32. Coulomb’s Law Inverse square Law: If distance is___________, F is _________. doubled¼ tripled1/9 quadrupled1/16

33. Current Electricity Current electricity involves electrons moving through conductors.

34. Current Def: How fast electrons flow past a fixed spot. Formula: Current is measured in Amps

35. Voltage Def: The amount of Potential Energy in a circuit. Voltage is measured in Volts.

36. Power Def: The amount of electricity that is used by an object. Power is measured in Watts

37. Resistance Def: Measure of how much electrons are slowed down when they go through a resistor. Resistance is measured in Ohms (Ω)

38. The Formulas (Ohm’s Law) Q It P IV V IR

39. Power Bills To calculate a Power Bill, Power must be in kilowatts and time in hours. Bill= rate*kW*h Kilo: 1000 (1000 Watts in 1 Kilowatt)

40. Practice Complete the practice problems for a classwork grade.

41. Circuits Two main types of circuits Series Circuit- One lane road Parallel Circuit- Interstate

42. Ohm’s Law- WHOLE Circuit What is R total for the circuit? What is the current? 5V 3 Ω 5 Ω

43. Ohm’s Law- EACH Resistor What is the voltage in each resistor? 5V 3 Ω 5 Ω

44. PARALLEL Circuits Which resistor has the greatest current flowing through it? 10V 2 Ω4 Ω

45. Magnets and Magnetic Fields Magnetic Fields are SIMILAR to electric fields. Consider the following magnet. 1 2

46. Magnets and Magnetic Fields Fact: Field Line ALWAYS leave the North Pole and enter the South Pole 1 2

47. Magnets and Magnetic Fields Which end is North and which is South? 1 2

48. Magnets and Magnetic Fields Which end is North and which is South? N S

49. Magnetic Fields- Right Hand Rules Use your right hand!!!!

50. Right Hand Rule #1 What does a magnetic field, B, look like around a wire? Grab some wire with your RIGHT hand I

51. Right Hand Rule #1 Make sure your thumb is going in the same direction as the current is! I

52. Right Hand Rule #1 Your 4 fingers are lined up with the magnetic field. It goes in a circle around the wire. I

53. Right Hand Rule #2 Right Hand Rule #2 tells us in what direction the wire will be pushed… N (+) S (-) B I

54. Right Hand Rule #2 Step 1- Index finger of RIGHT hand points in the direction of the current (I). I S N B

55. Right Hand Rule #2 Step 2- Point little finger in the direction of the magnetic field B. I S N B

56. Right Hand Rule #2 Step 3- Stick your thumb out. Which way is it pointing? I S N B INTO the page!

57. Right Hand Rule #2 This is the direction of the force on the wire. The wire will move INTO the page. I S N B INTO the page!

58. Generators Right Hand Rule #2 can be used to generate electricity as well…

59. Generators Any device that transfers mechanical energy into electrical energy is called a generator.