1. The problem statement, all variables and given/known data Two wires A and B are connected in series at 0oC and resistance of B is 3.5 times that of A. The resistance temperature coefficient of A is 0.04% and that of the combination is 0.1%. Find the resistance temperature coefficient of B. 2. Relevant equations Rt=R0(1+α0t) αt=α0/1+α0t 3. The attempt at a solution This is an example problem form A Textbook of Electrical Technology Vol. I. So the solution comes from that book: It is seen that RB/RA = 3.5 = 0.003/(0.001-α) --> α = 0.000143oC-1 My problem is that this relationship is not clear to me. From the looks of the given solution it is saying that: RB/RA=αA-αAB/αAB-αB and then solving for αB. I'm confused if this is the correct relationship and if so where it came from? How do you relate them without at least one other measurement at some other temperature?