P 4.3-10 Figure P 4.3-10 shows a measurement made in the laboratory. Your lab partner forgot to record the values of R₁, R₂, and R₃. He thinks that the two resistors were 10-kΩ resistors and the other was a 5-kΩ resistor. Is this possible? Which resistor is the 5-kΩ resistor?

Figure P 4.3-10

So we have three voltage nodes, one is 12 V, one is 4.50 V and the other is 6 V. So if we write the voltage node equations for either the 12 V or the 6 V we get

Neither provides any useful information. Writing the remaining voltage node equation does provide us with a useful equation

No matter what

So we have three possible equations

So the last equation works, so the choices of 10 kΩ for two and 5 kΩ for the other works and R₃ is the 5 kΩ

.

R₃ is the 5 kΩ

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