Stage 2 · Lesson 1 of 7
Ohm's law and power
is the push that moves charge, current is how much charge flows, and resistance opposes the flow. Ohm's law ties them together: V = I x R. Power, the rate a part turns energy into heat or work, is P = V x I.
These two formulas pick almost every resistor, confirm a pin can drive a load and estimate . Work in consistent units: volts, amps and ohms, or volts, milliamps and kilohms, which also works out. Buy a basic multimeter early and measure a few resistors and a battery so the numbers feel real.
Common trapmixing units, such as milliamps with ohms, and ending up a factor of 1,000 out, which in electronics means either nothing happens or something burns.
A question to check yourself, an AI practice session and 1 cheat sheet entry come with the full roadmap. Unlock
Resources for this stage
Start with
- BookFreeAll About Circuits Textbook
All About Circuits · Beginner
Free: read the DC volume chapters on Ohm's law, series and parallel circuits and dividers
Keep handy
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