Efield in Composite Wire..Pls help!! 1. The problem statement, all variables and given/known data A 2.0m length of wire is made by welding the end of a 1.2m long silver wire to the end of an 0.8m long copper wire. Each piece of wire is 0.60mm in diameter. The wire is at room temperature. A potential difference of 5.0V is maintained between the ends of the 2.0m composite wire. What is the magnitude of E in the copper? 2. Relevant equations E='roe'J , 'roe' is resistivity J=I/A, A is cross sectional area I= 45amperes A= 2.827*10^-7 sqm Resistivity of copper= 1.72*10^-8 Resistivity of silver= 1.47*10^-8 3. The attempt at a solution I tried to calculate J first by substituting in values of I and A using the formula J=I/A and multiplying by 'roe'_copper but i still cant get the right answer!! I would like to ask the concept behind the E of a composite wire too..