Journeyman Electrician Exam (NEC)General Electrical Knowledge and Plan ReadingMedium
A technician is troubleshooting a 120V AC circuit that has two loads connected in parallel. Load 1 draws 5A and Load 2 draws 8A. What is the total current drawn from the source?
- A3A
- B13A
- C16A
- D6.5A
Show answer & explanationAnswer & explanation
Correct answer: B. 13A
In a parallel circuit, the total current drawn from the source is the sum of the currents flowing through each individual branch (load). Therefore, Total Current = I1 + I2 = 5A + 8A = 13A.
Why the other options are wrong
- A. This would be the difference if the currents were opposing or if one was subtracted.
- C. Incorrect calculation.
- D. This is an average, not a sum.
Total Current in Parallel Circuits
According to Kirchhoff's Current Law (KCL), the total current entering a junction (or leaving the source) in a parallel circuit is equal to the sum of the currents flowing through each branch.
- Voltage is the same across all parallel branches.
- Current divides among the branches.
- Total resistance in parallel is less than the smallest individual resistance.
- KCL is fundamental to parallel circuit analysis.
Memory trick: Parallel paths, current adds, voltage stays.