Chapter 7: Questions 8, 9, 12. Problems 13, 14.
Q7.8
Electric field is the force per unit charge that a given charge distribution will exert on an additional charge placed nearby.
That is E = F/q acted on. For a proton, the field lines look as below.
Q7.9
Q7.12
Insulators conduct very, very little electricity. They are used to prevent current flow.
Semiconductors conduct better, but still not very well. They are used in many solid state electronics devices, as well as for temperature sensors.
Conductors conduct electricity very easily. They are used to make electrical wires.
Superconductors conduct electricity with no resistance at all. They are used for very powerful magnets that require no power after the current is initially started.
P7.13
P7.14
