1. Consider each of the following situations in a qualitative way and determine the equation type, the nature of the boundary curve and the type of boundary conditions involved:
a. a conducting bar given an initial temperature distribution and then thermally isolated;
b. two long conducting concentric cylinders, on each of which the voltage distribution is specified;
c. two long conducting concentric cylinders, on each of which the charge distribution is specified;
d. a semi-infinite string, the end of which is made to move in a prescribed way.