Some Old (Looks like a lot, but it's mostly review and pretty easy problems -- looks a lot like Friday's assessment *hint*:

Metric (show work):

1. Convert 32 km to meters

2. Convert 1,234 mm to meters

3. Convert 127 cJ to kJ

Electrostatics Lab

3. Imagine you are given the following: a piece of PVC (which behaves like black plastic or amber) and a piece of acetate plastic (which behaves as rabbit fur), a rod of unknown material and piece of waxed paper. The task is to determine the charge that the waxed paper leaves on the rod. What charge is now on the electroscope?

4. You rub the PVC with acetate then touch it to an electroscope. The leaves of the electroscope diverge and stay diverged when the PVC is put away. You then rub the unknown material with waxed paper and bring it near but not touching the electroscope. The leaves get closer together (slightly). What charge is on the unknown rod? How do you know? Describe the motion of electrons in the electroscope in each phase of the experiment.

Electrically charged particles

5. What particles make up a proton? What is the charge on each of those particles and on the proton (in terms of multiples of the elementary charge).

6. What particles make up a neutron? What is the charge on each of those particles and on the proton (in terms of multiples of the elementary charge).

7. Discuss the composition of an ion in terms of the number of protons and electrons present.

8. Discuss how polarization makes possible the attraction of a neutral (always neutral -- it never acquires a net charge) object to a charge rod that has either positive or negative character.

Coulomb's Law

9. What happens to the force between two particles when the distance between them is:

10a. doubled

10b. tripled

10c. increased by a factor of 2.7

11. What happens to the force between two charged particles when the charge of one is doubled?

12. What happens to the force between two charged particles when the charge of one is doubled and the charge of the other is taken times 2.5?

13. What happens to the force between two charged particles when the charge of each is multiplied by 5 and the distance between them is divided by 3.2?

Ohm's Law

14. What current does 6 V push through an 8 Ω wire?

15. What potential is required to produce 2 A in a 12 Ω wire?

16. What resistance gets .5 A of current under the influence of 5 V of potential?

17. What is the symbol and unit of electric potential?

18. What is the symbol and unit of electric current?

19. What is the symbol and unit of electric resistance?

Resistor Networks

20. What is the resistance where a 1 Ω, 2 Ω and 3 Ω resistance are placed in series? Draw a schematic for the circuit in your notes.

21. What is the resistance where a 1 Ω, 2Ω and a 3 Ω resistance are placed in parallel? Draw a schematic for the circuit in your notes.