Answer
The potential difference across each section of wire is $~~0.00216~V$
Work Step by Step
The resistivity of copper is: $~~\rho = 1.69\times 10^{-8}~\Omega \cdot m$
We can find the resistance in each section of wire:
$R_w = \frac{\rho~L}{A}$
$R_w = \frac{\rho~L}{\pi~r^2}$
$R_w = \frac{(1.69\times 10^{-8}~\Omega \cdot m)(0.20~m)}{(\pi)(1.00\times 10^{-3}~m)^2}$
$R_w = 0.00108~\Omega$
We can find the total resistance of the circuit:
$R = 0.00108~\Omega+6.00~\Omega+0.00108~\Omega$
$R = 6.00216~\Omega$
We can find the current in the circuit:
$i = \frac{12.0~V}{6.00216~\Omega} = 1.99928~A$
We can find the potential difference across each section of wire:
$\Delta V = i~R_w = (1.99928~A)(0.00108~\Omega) = 0.00216~V$
The potential difference across each section of wire is $~~0.00216~V$
