1. Unit D Review Electricity

2. How can you explain two charged objects “sticking” to one another? Opposite charges, movement of electrons!

3. What are some common examples of static electricity? Static cling (laundry), lightning, rubbing a balloon on your hair!

4. How is current electricity different from static electricity? It is in motion!

5. A good conductor will typically have ________ resistance. Low

6. How does a fuse work? When too much electricity passes through it, a thin strip of metal inside of it will melt, causing the circuit to break.

7. What type of energy conversion occurs inside a thermocouple? Thermal energy  electrical energy

8. What makes up a basic electrochemical cell? An electrolyte (liquid or paste) and two electrodes (different metals!)

9. What is an ohmic resistor? Resistance is constant regardless of current or voltage applied.

10. What is the difference between a semiconductor and a superconductor? Superconductor – practically no resistance!

11. What is the purpose of a switch in a circuit? Completes the circuit; allows electricity to flow.

12. A wire has a resistance of 20 ohms. If 10A of current passes through the wire, what is its voltage? V = I x R = 10A x 20 ohms = 200 V

13. On a strand of Christmas lights, one bulb is burnt out but the rest of the strand still works. How can this be so? Parallel circuit.

14. What is the difference between a cell and a battery? A battery is made up of a number of cells.

15. Provide an example of a load that might be found in a circuit? Lightbulb, motor, electrical device, etc.

16. What is energy? The ability to do work!

17. What is the SI unit for energy? Joule, J

18. What type of energy conversion is occurring in a BBQ? Chemical potential (propane)  Thermal

19. What is an electromagnet? When a magnet is passed through a coil of wire, an electrical current is produced OR When a current is applied to a coil of wire with a specific core, a magnetic field is generated.

20. A hairdryer is connected to a 120 V outlet, with 15A of current flowing through it. What is the power of the hairdryer? P = I x V = 15A x 120V = 1800 W

21. How does thickness of a wire affect resistance? Thinner wire = more resistance!

22. How do you calculate efficiency of an electrical device? (Useful output energy / Total input energy) x 100