# Charge accumulation at a bi-metallic junction

When we join two straight cylindrical wires of two different metals say 'iron' and 'copper' together such that their circular faces are in contact. If we make a constant current say I through the wires then is any charge is accumulated at the junction . To me it seems that there would be some charge as we have $$I = neAv$$ and the $$nAv$$ term for both can't be different as I is same through both ? I am very confused any help would be appreciated. Thanks in advance😊

• n and v will fix things I guess. – Jasper Nov 22 '18 at 20:47