1. Static Electricity Charging Neutral Objects

2. Electric charge can be influenced to move by the presence of other charges (same or different) To produce a net charge on a previously neutral object, electrons need to be added to or removed from the object This can be accomplished in two ways

3. Charging Neutral Objects The first way to charge an object is by contact If I bring a charged object in contact with a neutral object, some of the charge will transfer to the neutral object and it will become charged Since charges move from the charged to the neutral object, this is called charging by Conduction

4. Charging by Conduction To summarize: Charging by conduction involves contact between the charged object and the neutral object = + = - Neutral Charge = -6e

5. Charging by Conduction To summarize: Charging by conduction involves contact between the charged object and the neutral object = + = - Charge = -1e Charge = -5e

6. Charging by Conduction To summarize: Charging by conduction involves contact between the charged object and the neutral object = + = - Charge = -2e Charge = -4e

7. Charging by Conduction To summarize: Charging by conduction involves contact between the charged object and the neutral object = + = - Charge = -3e

8. Charging by Conduction Once the two objects have the same charge, no more charge is transferred!!! The net charge overall is still -6e because electric charge is conserved = + = - Charge = -3e

9. Charging by Induction The second way to charge an object is when there is no direct contact between the charged object and the neutral object Charges are influenced in the neutral object, but no transfer occurs with the charged object This method is called charging by Induction

10. Charging by Induction Here is how it works: I start with two neutral conductors (this won’t work very well with insulators) that are in contact with each other but are not grounded = + = -

11. Charging by Induction Here is how it works: I bring a charged object nearby the two conductors, but it does not make contact with either conductor = + = - both are neutral charge = -3e

12. Charging by Induction Here is how it works: The charged object pushes electrons from the right- hand sphere to the left-hand sphere = + = - charge = -3e

13. Charging by Induction Here is how it works: The charged object pushes electrons from the right- hand sphere to the left-hand sphere = + = - charge = -3e

14. Charging by Induction Here is how it works: The charged object pushes electrons from the right- hand sphere to the left-hand sphere = + = - charge = -3e

15. Charging by Induction Here is how it works: Now, I move the left-hand sphere away from the right-hand sphere, while the charged object is still nearby = + = - charge = -3e

16. Charging by Induction Here is how it works: Now, I move the left-hand sphere away from the right-hand sphere, while the charged object is still nearby = + = - charge = -3e

17. Charging by Induction Here is how it works: Now, I move the left-hand sphere away from the right-hand sphere, while the charged object is still nearby = + = - charge = -3e

18. Charging by Induction Here is how it works: Now I can take the charged object away = + = - Notice what happens - - - The left-hand sphere has three extra electrons (charge = -3e) The right-hand sphere has lost three electrons (charge = +3e)

19. Charging by Induction Both objects are now charged!!! Without either one making contact with the charged object = + = - The net charge between the two is still 0 This is because electric charge is conserved - all charge gained by one is lost by the other! charge = -3echarge = +3e