Compute the voltage drop along a 25 m length of household no. 14 copper wire (used in 15A circuits). The wire has diameter 1.628 mm and carries a 15 A current. Vdrop=I*R R=rho(L/A) I just plugged the resistivity of copper wire which is 1.72*10^-8, length, and area in to find the resistance. Which is .206 and then I found the voltage drop of 3.09v which was wrong what did i do wrong?