In a wire with a 189mm2 crosssectional area 721 x1020 electr

In a wire with a 1.89-mm2 cross-sectional area, 7.21 x1020 electrons flow past any point during 3.09 s What is the current in the wire? Number Find the current density. Number A/m2

Solution

given wire with cross sectional area A = 1.89*10^-6 m^2
time t = 3.09 s
numbe rof electrons n = 7.21*10^20
hence
current = i = n*e/t = 37.33 A

curent density = i/A = 19.753*10^4 A / m^2