A 20 A circuit has a design current of 18 A and voltage drop of 19.5 \( \mathrm{mV} / \mathrm{A} / \mathrm{m} \). If its circuit length is 25 m, what is the overall voltage drop ?

To calculate the overall voltage drop in the circuit, you can use the following formula: \[ V_{\text{drop}} = (\text{Voltage drop per A per m}) \times \text{Current} \times \text{Length} \] **Given:** - Voltage drop per A per m = 19.5 mV/A/m - Current = 18 A - Length = 25 m **Step-by-Step Calculation:** 1. **Convert millivolts to volts:** \[ 19.5 \, \text{mV/A/m} = 19.5 \times 10^{-3} \, \text{V/A/m} \] 2. **Multiply by current and length:** \[ V_{\text{drop}} = 19.5 \times 10^{-3} \, \text{V/A/m} \times 18 \, \text{A} \times 25 \, \text{m} \] 3. **Calculate the numerical value:** \[ 19.5 \times 18 = 351 \] \[ 351 \times 25 = 8775 \] \[ 8775 \times 10^{-3} = 8.775 \, \text{V} \] 4. **Round to two decimal places:** \[ V_{\text{drop}} \approx 8.78 \, \text{V} \] **Final Answer:** The overall voltage drop is approximately **8.78 V**.