1. 1.Alternating current can be converted to ________ current using a ______. 2. Charges move easily through _____________ but cannot move through ___________. 3. Draw a series circuit with two bulbs in it. directdiode a conductor an insulator

2. 4. transistor – 5. solenoid – 6. resistance – 7. diode – 8. static electricity – 9. magnet – 10. electricity - semiconductor device that can be used as an amplifier or a switch a coil of wire that produces a magnetic field when carrying an electric current opposition to the flow of electric current semiconductor device that only allows electricity to flow one direction. It can convert AC to DC. the buildup of electrical charges on an object any material that attracts iron or materials which contain iron. the flow of electrons

3. 11. Draw a parallel circuit with three bulbs in it. 12. How does a circuit board work? A circuit board is a collection of hundreds of tiny circuits mounted on a “board” that together supply electric current to the various parts of an electronic device.

4. 13. If a charged object goes near an electrically neutral surface (but doesn’t touch it), then it can be charged through ___________. However, if there is direct contact, the surface is charged by _____________. 14. If three solenoids all have the same number of loops but different magnetic fields, what must be different? induction conduction More iron in the core, more current (like a bigger battery), or shorter wires (less resistance)

5. 15. If two charges are the same, they will _______ each other. 16. If you rub a piece of plastic with felt, the plastic becomes charged by _________. 17. In a parallel circuit, no matter how many bulbs you add, they will all have the _______ brightness. 18. Lightning is an example of ____________________; this is the loss of static electricity as charges move off an object. repel friction same electrical discharge

6. 19. Transistors and diodes are both made of _______________ material. 20. When an object gains or loses ____________, it becomes charged. 21. Name 3 things that will decrease resistance. semiconductor electrons a.use a thicker wire b.use a shorter wire c.cool the temperature d.use a material that is a good conductor

7. 22. Name 3 ways to make an electromagnet stronger: 23. Name 2 ways to increase the magnetic field of a solenoid. increase the number of coils in the solenoid put more iron in the core increase the current (bigger battery) use a shorter wire for less resistance more coils put an iron core in the solenoid use more current (bigger battery)

8. 24. Technology can be much smaller today because of 25. The law of electric charges states: 26. What is the difference between alternating and direct current? In direct current, the charges always flow in one direction. In alternating current, the charges constantly switch directions, moving back and forth.

9. 27. What is the difference between an electric motor and a generator? Electric motor converts Electrical to Kinetic energy. Generator converts kinetic energy to electrical energy. 28. How does electromagnetic induction work? Using electromagnetic induction, you can produce an electrical current by changing a magnetic field. For example, if you move a magnet around in a coil of wire, you can produce an electric current.

10. 29. A 100 Ω resistor is connected to a 20 V supply. What current flows through it? (Show your work and include units!) 30. Calculate the voltage across a 300 Ω resistor when a current of 0.004 A flow through it. (Show your work and include units!) Factor in Ohm’s Law SymbolUnitSymbol for Unit 31.ResistanceROhmΩ 32.CurrentIAmpereA 33.VoltageVVoltsV

11. 34. You’re putting up a set of LED lights that are a bit fragile. You’re adding them to a circuit with a brand new 9V battery. Assuming there is no resistance from the attached ammeter or the wires, how much resistance is there in each LED light?