Problem 12-6    Source:    Problem 4.19 - page 168 -    IRWIN, J. David -    Book: Análise de Circuitos em Engenharia - 4ª edição -   Ed. Pearson - 2013.

In the circuit show in Figure 12-06.1, calculate V_o and I_o.

Solution of the Problem 12-6   -    Nodal Voltage Method

Looking at the circuit, we clearly notice the following equality:

Let's write the equation for the node V₁.

And to the node V₂ we can write that:

Remembering that V₁ = 2 I_o and making substitution in the last equation, we arrive at the following conclusion:

Using this information in the other equation, we were able to find the values requested in the problem, or:

And I_o is:

Note that by the 2 ohms resistor that lies between the nodes V₁ and V₂, no current flows.