Building on the entry-level foundation, this guide moves from concepts to numbers — the actual calculations, circuit reading, and basic test-equipment skills a mid-level operator is expected to perform and understand on the exam and on the job. If you can already explain voltage, current, and resistance using the water analogy, you're ready to start applying Ohm's Law with real numbers, reading a panel schedule, and safely using a multimeter to check a de-energized circuit.
Ohm's Law: Solving for Any Unknown
Ohm's Law, V=I×R, can be rearranged algebraically to solve for whichever quantity is unknown: I=RVR=IVV=I×R Worked Example 1 — Finding Current: A circuit operates at 120 volts with a resistance of 60 ohms. What is the current?
I=RV=60 Ω120 V=2 A **Worked Example