Hello, I have simple circuit shown below, my question is how to find i0 and v0 plus why there are "+" and "-" signs next to 8 Ohm resistor ? Resistors doesn't have polarity, so what it means ?
In the circuit you have an independent current source (the left-most), a current source that generate a current of ampliteude depending from the current flowing in the 2 ohm resistor and two resistors in parallel.
You need to apply Ohm's law, but also Kirchoff's law. The exercise is easy to solve.
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The + and - symbol is to measure the volatge output. Which will give you the postive volatge level if you reverse the leads while measuring obviously it will give you a negative voltage. You should not connect any loads in a opposite direction.