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VTh = 30 v x 1 k ohm / (1 k ohm + 2 k ohms) = 10 v When the battery E is replaced by a short circuit, R1 and R2 are in parallel and their equivalent resistance is RTh = 666.7 ohms. The circuit would be that of Figure 1.9 except the values will be the ones calculated here. ................
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