TechnologyThe ProfessorBeginner
Circuit Basics: Ohm's and Kirchhoff's Laws, a free technology course on Tomo

Circuit Basics: Ohm's and Kirchhoff's Laws

Master the core rules that govern how electricity moves through wires, components, and junctions. Learn to calculate voltage, current, and resistance in simple circuits, and use those insights to troubleshoot real hardware issues. Gain the foundational intuition needed to build, analyze, and debug basic electronics.

Like Duolingo, but for Circuit Basics: Ohm's and Kirchhoff's Laws. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.

A short one: 12 levels across 2 sections, about 24 minutes end to end, roughly 5 days at five minutes a day. It moves through Single Loops: Voltage, Current, and Drops and Branching Networks: Junctions and Diagnostics. It starts from scratch.

12 bite-size levelsAbout 5 minutes each

Free forever · No credit card · iPhone & Android

Ollie the Ohm Owl, the guide who teaches the Circuit Basics: Ohm's and Kirchhoff's Laws course
Circuit Basics: Ohm's and Kirchhoff's Laws
with Ollie the Ohm Owl
12
Levels
2
Sections
5
Min/day
What you'll learn

Key ideas in Circuit Basics: Ohm's and Kirchhoff's Laws

  • Voltage is the electrical pressure provided by a source like a battery
  • Current is the actual rate at which electrical charge moves through a conductor
  • Resistance is the physical property of materials that slows down charge flow
  • Ohm's Law states that current equals voltage divided by resistance (I = V / R)
  • Dividing 9 volts by 3 ohms gives a current flow of 3 amps
  • If resistance remains constant, doubling voltage doubles current; if voltage remains constant, higher resistance reduces current
  • Components like LEDs have very low internal resistance and will draw destructive amounts of current if connected directly to a power source
  • Adding a resistor in series directly limits the total current flowing through that branch of the circuit
  • Resistors dissipate excess electrical energy safely as a tiny amount of heat to safeguard delicate components
  • A short circuit provides an unintended path of near-zero resistance between power and ground
  • Linking the core electrical properties to what they physically do in a circuit
  • According to Ohm's Law, when resistance drops toward zero, current spikes dramatically
  • Extreme current surges generate rapid heating, which can melt insulation, ruin batteries, or blow fuses
  • A multimeter measures resistance and continuity by injecting its own tiny test current, which is disrupted or damaged by external circuit power
  • Resistance must always be measured on fully unpowered, de-energized components
  • Voltage and active operating current can only be measured when the circuit is actively powered and running
Why not just Google it

You've tried the other tabs

Wikipedia

Thirty open tabs. Four facts you actually kept.

YouTube

You watched. You nodded. By Sunday it was gone.

ChatGPT

One answer, then back to scrolling.

Online courses

Eight weeks. You meant to finish. You didn't.

Tomo gives Circuit Basics: Ohm's and Kirchhoff's Laws the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.

Try a question

Here's what playing it feels like

A real question from this course. Take your best guess.

Pressure, Flow, and Resistance Basics

What is electric current in a wire?

Get it right to open this lesson and 11 more in the app.

Course map

Where Circuit Basics: Ohm's and Kirchhoff's Laws takes you

  1. 1

    Single Loops: Voltage, Current, and Drops

    • Predicting Flow with Ohm's Law
    • Tracing Voltage Around a Closed Loop
  2. 2

    Branching Networks: Junctions and Diagnostics

    • Splitting Current at Circuit Junctions
    • Diagnosing Circuit Faults with Node and Loop Rules

2 sections · 4 units · 12 levels. Built to play, not to enroll.

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Circuit Basics: Ohm's and Kirchhoff's Laws is taught in the Professor style: clear, structured, thorough. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.

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