After breaking down the circuit and solving for the total equivalent resistance, using the given applied voltage, the total current can be calculated with ...; then working back up through your redraws, the component current and voltage values can be determined.

After breaking down the circuit and solving for the total equivalent resistance, using the given applied voltage, the total current can be calculated with ...; then working back up through your redraws, the component current and voltage values can be determined.

• A. IT = I1 + I2 + I3 + ... IN
• B. IT = I1 = I2 = I3 = ... IN
• C. It = Et/ Rt
• D. It = Pt/ Et

Answer: (D)

The main idea is the relationship between power, voltage, and current: P = V I. Rearranging gives I = P / V. In a DC circuit with a single voltage source, the total current drawn from the source times the applied voltage equals the total power the circuit consumes. So, once you’ve determined the total power Pt that the circuit uses (which you can sum from the component powers as you work through the redraws), dividing Pt by the applied voltage Et gives the total current It from the source. This approach is particularly handy because it ties together the energy flow in the whole network and lets you step back from the detailed resistance distribution to get the overall current first, then back-calculate the branch currents and voltages. You could also use I = V/R with the total resistance, but the method phrased in the question emphasizes the power-based relationship, which makes D the best fit.

The main idea is the relationship between power, voltage, and current: P = V I. Rearranging gives I = P / V. In a DC circuit with a single voltage source, the total current drawn from the source times the applied voltage equals the total power the circuit consumes. So, once you’ve determined the total power Pt that the circuit uses (which you can sum from the component powers as you work through the redraws), dividing Pt by the applied voltage Et gives the total current It from the source. This approach is particularly handy because it ties together the energy flow in the whole network and lets you step back from the detailed resistance distribution to get the overall current first, then back-calculate the branch currents and voltages. You could also use I = V/R with the total resistance, but the method phrased in the question emphasizes the power-based relationship, which makes D the best fit.