The following images show cross-sections of electrical cables.
A closed path is shown as a dashed line. The magnetic voltage $\theta$ on these paths shall be analyzed.
The following values are given for the currents:
$I_1 = 5 {~\rm A}$
$I_2 = 2 {~\rm A}$
$I_3 = 1 {~\rm A}$
$I_4 = 4 {~\rm A}$
Specify which magnetic voltages $\theta_{(1)}$, $\theta_{(2)}$, and $\theta_{(3)}$ result.
Note the direction of the path in each case!
Path
For the resulting current the direction of the path has to be considered with the right-hand rule:
$I_{(1)} = +I_2 - I_1 - I_3 \quad \rightarrow \quad \theta_{(1)} = 2 {~\rm A} - 5 {~\rm A} - 1 {~\rm A} $
$I_{(2)} = +I_3 + I_4 - I_1 \quad \rightarrow \quad \theta_{(2)} = 1 {~\rm A} + 4 {~\rm A} - 5 {~\rm A} $
$I_{(3)} = +I_3 - I_4 - I_2 \quad \rightarrow \quad \theta_{(3)} = 1 {~\rm A} - 4 {~\rm A} - 2 {~\rm A} $
Result
\begin{align*}
\theta_{(1)} &= -4 {~\rm A} \\
\theta_{(2)} &= 0 {~\rm A} \\
\theta_{(3)} &= -5 {~\rm A} \\
\end{align*}