A 5m long copper rod with a diameter of 12mm has resistivity ( ρ ) of 1.76 x Ωm, calculate its resistance.
Answer (1)
Resistance (R) can be calculated using the formula:[tex]R = \frac{\rho L}{A}[/tex]where ρ is the resistivity, L is the length, and A is the area.To calculate the area, we must first find the radius of the rod in meters:radius = diameter/2radius = 12 mm/2radius = 6 mm = 0.006 mNow, calculating for the area:[tex]A =\pi r^2\\A = \pi (0.006 m)^2\\A= 0.0001131 m^2[/tex]Calculating the resistance:[tex]R = \frac{(1.76\times 10^-8 \Omega m)(5 m)}{0.0001131 m^2} \\R = 7.78\times 10^{-4} \Omega[/tex]Hence, the resistance of the long copper rod is [tex]7.78 \times 10^{-4} \Omega[/tex].
