Question

a copper wire has a square cross section 2.0 mm on a side.it is 4m connected to a power supply of 10v,the resistivity of copper is 1.7*10^-8 Ω what is the current density

Answer 1

Answer:

  1.47·10^8 A/m^2

Explanation:

The current density is ...

  J = E/(ρ·L) = 10 V/((1.7·10^-8 Ω·m^2/m)(4 m)) = 1.47·10^8 A/m^2