Preparation Notes for Week 2:

-What are you supposed to bring to class?  (Ans: book & calculator)

-What are you supposed to bring to lab?  (Ans: book, calculator, bound notebook with graph paper, $15 to buy LabNotes)

-The biggest thing you should be able to answer from doing this reading: why in V=IR we apply a constant force but get a constant velocity?  This is contrary to physics: F=ma we should have a constant acceleration resulting in a changing velocity!

-How does the resistivity of a metal change with temperature (and why)?  What would happen to the conductivity of a circuit (say a computer chip) if you heated it up?

 -Review the derivation for J.  If J = I/A, where is the area term in J=envdx?

-What are some things that cause an electron to be scattered?  What does this do to the electron's velocity?

-What's drift mobility?  What is it's units?

-What's the relationship between the mean time between collisions and the probability of being scattered?

-Example 2.2 calculates the free electron concentration and mobility of Cu.  How would the free electron concentration of Cu change if the atom had 2 valence electrons?  Using the data on page 681, repeat the calculation for Zn instead of Cu (look up the conductivity of Zn).

-How does resistivity change with temperature in a pure metal?  Why?