Answer
See answers.
Work Step by Step
a. Use Ohm’s law to find the resistance.
$$R=V/I=(22.0\times10^{-3}V)/(0.75A)\approx 0.029 \Omega$$
b. Find the resistivity using equation 18–3.
$$R=\frac{\rho L}{A}$$
$$\rho=\frac{RA}{L}=\frac{R \pi r^2}{L}$$
$$\rho=\frac{(0.02933 \Omega) \pi (0.001m)^2}{4.80m}=1.9\times10^{-8}\Omega \cdot m$$
c. Use equation 18–10.
$$n=\frac{I}{eAv_d}=\frac{0.75A}{(1.60\times10^{-19}C) \pi (0.001m)^2(1.7\times10^{-5}m/s)}$$
$$n=8.8\times10^{28}e/m^3$$
