Physics

Physics

Problem

In a laboratory exercise a 100 cm100\,\text{cm} long nichrome wire of cross-sectional area 0.20 mm20.20\,\text{mm}^2 conducts a current of 2.5 A2.5\,\text{A} when connected to a 4.0 V4.0\,\text{V} source. The free–electron number density for nichrome is 9.0×1028 m−39.0\times10^{28}\,\text{m}^{-3}. a. (i) Determine the resistivity of nichrome from the measurements. b. (ii) Using this resistivity, calculate the electron mobility in the wire. c. (iii) If a second wire of the same dimensions is made from a material whose electron mobility is 1.51.5 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 4.0 V4.0\,\text{V} source is applied.

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