In a laboratory exercise a 100cm long nichrome wire of cross-sectional area 0.20mm2 conducts a current of 2.5A when connected to a 4.0V source. The free–electron number density for nichrome is 9.0×1028m−3.
(i) Determine the resistivity of nichrome from the measurements.
(ii) Using this resistivity, calculate the electron mobility in the wire.
(iii) If a second wire of the same dimensions is made from a material whose electron mobility is 1.5 times the value obtained in part (ii) (with the same number density of charge carriers), find the current that would flow through it when the same 4.0V source is applied.