2. The shocking truth about

3. Electricity is electrons. Electrons that are not moving is Static electricity. Electrons build up until the like charges in the electrons cause them to repel each other and move to a ground. A ground is an area that is more positive. + + + + + - - - - - - - -

5. An object can be given a charge by one of three ways: 1) Conduction - if a charged object is put near an uncharged object, the uncharged object will up or take electrons. + + – – + + – – – – – + + – – Electron movement

6. An object can be given a charge by one of three ways: 2) Induction - if an electrically polarized object is put near an unpolarized object, the electrons will move causing both objects to be polarized. + + – – + + – – – – + + – – + +

7. An object can be given a charge by one of three ways: 2) Induction - if an electrically polarized object is put near an unpolarized object, the electrons will move causing both objects to be polarized. + + – – + + – – – – + + – – + +

8. An object can be given a charge by one of three ways: 3) Friction - if two objects are rubbed together, electrons from one can be rubbed off onto another.

9. An object can be given a charge by one of three ways: 3) Friction - if two objects are rubbed together, electrons from one can be rubbed off onto another.

10. Current = flowing electrons. But why do electrons move? When one object (or part of an object) is positively charged and another is negatively charged, electrons will move from the negative to the positive. The difference in charges between the positive and negative is called electrical potential difference. This potential difference is the voltage. Voltage is the amount of energy per charge (or electron). The number of charges that move per unit time is the current, which is measured in amperes (amps).

11. In other words, the amount of work that each charge can do is the number of volts. The amount of charges is the number of amps.

12. Mathematically, voltage is V=V= W q an d Current is I=  q  t

13. Resistance As with other moving objects, resistance is the impediment to movement. In the case of electricity, resistance prevents charges from moving. Resistance depends on the make up of the substance that the current is passing through and the length of the substance. Mathematically, voltage is R=R= V I

14. Ohm’s Law - substances that have the same resistance regardless of the voltage. Most metals obey Ohm’s law for to a certain extent. Devices that do not obey ohms law would be light bulbs, transistors and diodes. The resistance that these objects exhibit depends on the voltage that they receive. Potentiometers (rheostat) - a device that uses the length of wire that a current is passing through to control the resistance. + –

15. Circuits - a simple circuit contains a power source, wires to conduct the current and a source of resistance (other than the wires). + –

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17. In a circuit, electricity moves like water. It flows down the electrical gradient and when there is a break, the electricity will not flow. There are two main types of circuits parallel and series. Series circuits- a circuit in which there is one path and all of the devices are along this path. In series circuits, all devices have the same amount of current. However, each device will use some of the energy from the charges and will produce resistance. Parallel Circuits - a circuit in which the path between the positive and negative charges branches and then re- converges. In this circuit, the current is additive, the voltage is the same for all devices and the inverse of the resistance is the sum of the inverse of each resistance.