Question

Why should the potentiometer wire be of uniform cross section and composition?

Answer 1

The ear responds to an increase in column in a logrithmic fashion so a non-linear control works better. The linear taper control works with a uniform resistance change vs rotation or slide. The audio taper is made with a non-linear change. So if a wire based unit is used a non constant cross section would be used.

Answer 2

Think about how you are going to use it. You are going to find a null point by moving a slider up and down it. Then convert the length ...