A cylindrical aluminium wire of length 3.0m and radius 1.0mm is connected to a dc source that maintains a potential difference of 6.0V between its ends. For aluminium, the resistivity at room temperature is 2.8×10−8Ωm and the number density of free electrons is 6.0×1028m−3. Take e=1.6×10−19C.
(i) Calculate the resistance of the wire and the current flowing through it.
(ii) Determine the drift velocity of the electrons in the wire.
(iii) The wire is now uniformly stretched to double its original length, keeping its volume constant, and is re-connected to the same 6.0V supply. Calculate the new drift velocity of the electrons.