Download circuits and current review

TEST REVIEW PHYSICS
For the test over current and circuits you should know:
1. What two things are needed for charge to flow between two points?
2. What is actually flowing in a current carrying wire?
3. What is an ampere?
4. The resistance of a wire depends on what three factors?
5. Which has more resistance, a thick wire or a thin wire?
6. What is the unit of resistance? of power?
7. State the formula for Ohm’s law.
8. What is grounding, and why is this important in home circuits?
9. What is the voltage and frequency of household current? Is it ac or dc?
10. What is the approximate net speed (drift speed) of electrons in a circuit?
11. Do we get electrons from the power company? What are we really paying for?
12. What is the unit of energy used by the power company?
13. Which gets used up in a circuit, the voltage or the current?
14. How does the current compare in different parts of a series circuit?
15. What happens to the current in a parallel circuit?
16. How do the voltage drops across parallel branches of a circuit compare?
17. How are the voltage drops (potential differences) around a series circuit related to the source
voltage?
18. If one bulb burns out in a series circuit of lights, what happens to the other bulbs?
19. What are the schematic symbols for the resistor, battery cell, and connecting wire?
20. Does a battery produce dc or ac?
21. How does the total resistance of a parallel combination of resistors compare with each individual
resistor?
22. How are the circuits in our home connected together?
23. What is the function of circuit breakers and fuses?
24. What is the total resistance if a 4-ohm and an 8-ohm resistor are connected in series? In parallel?
25. How much power does a device drawing 2 amps on a 6-volt line use?
26. What is the current through a 20-ohm resistor when connected to a 9 V battery?
27. How much will it cost to run a 10 A vacuum for 6 hours at $0.10/kWhr (at 120 V)