Problem 13-3    Source:    Problem elaborated by the author of the site.

Calculate the currents in the circuit shown in the Figure 13-03.1.

Solution of the Problem 13-3   -    Kirchhoff Method

In the figure above, we see the circuit showing the direction (clockwise) of the currents I₁ , I₂ and I₃. Note that the current source is on the periphery of the circuit. With this, in advance we already know that the value of I₃ is:

So let's write the mesh equations beginning with I₁. So:

Now, by doing the mesh to I₂.

But how I₃ = 24 A, doing the calculation and rearranging the terms, we arrive at:

Therefore, we have a system of two equations with two unknowns. After calculations we find the values of I₁ and I₂.

Knowing the values of I₁ and I₂, the Figure 13-03.2 shows how the distribution of the currents in the circuit was.

Note that I₁ circulates between points d-c and I₂ between the points a-d. In other points we have to take into account the subtractions of the currents corresponding to the loops. For example, between points a-b , the current is I₃ - I₂ = 24 - 15 = 9 A. For the other points the procedure is the same.