Final answer:
The node-voltage method is a technique used to analyze electrical circuits and find the power associated with each source. Positive power indicates delivery to the circuit, while negative power indicates extraction from the circuit.
Step-by-step explanation:
The node-voltage method is a technique used to analyze electrical circuits. To find the power associated with each source in the circuit, we first need to find the voltage across each source. Then, we can use the formula P = V*I to calculate the power, where P is the power, V is the voltage, and I is the current flowing through the source.
If the calculated power is positive, the source is delivering power to the circuit. If the calculated power is negative, the source is extracting power from the circuit.
For example, if we have a voltage source of 10 volts and a current of 2 amperes, the power would be P = 10*2 = 20 watts. Since the power is positive, the source is delivering power to the circuit.