Current & Voltage Course

Lesson 5 of 16: Ohm's Law Basics

Move step by step through the course and keep track of where you are.

Simulation

Ohm's Law Basics

Ohm's Law connects voltage, current, and resistance. If you know any two values, you can calculate the third.

Voltage

12.0 V

Current

2.00 A

Resistance

6.00 Ohm

Core idea

Voltage is the push, current is the flow, and resistance is the opposition. Ohm's Law shows exactly how they affect one another.

Simple idea

More voltage gives more push. More resistance gives more opposition. Ohm's Law helps you see the result.

Ohm's Law in ActionVoltage pushes charge. Resistance controls flow. Current = 2.00A. Flow level: HIGH+12.0V12RESISTOR 6.0 OhmakLEDVoltage PushCharge Flow ->Charge Flow Strength: 67%
Formula View

Watch Ohm's Law solve the missing value

This simulation shows how one law connects all three circuit values. When two known values change, the third one updates automatically.

Solve mode

Solve I

Choose the unknown value and let the other two values determine the answer.

Formula

I = V / R

I = V / R = 12 / 6 = 2 A

Circuit effect

Fast Flow

Higher current makes the LED brighter. Higher resistance pushes the current down.

What to notice

The formula is not separate from the circuit. It is simply a short way to describe what the circuit is already doing.

Beginner Summary

Keep this Ohm's Law picture in mind

This lesson becomes easier when you remember one clear picture: voltage gives the push, resistance pushes back, and current is the final flow that we can measure.

If any two values are known, Ohm's Law helps you calculate the third value quickly and clearly.

Voltage

Voltage is the push that tries to move charge through the circuit.

Current

Current is the amount of charge that actually moves through the path.

Resistance

Resistance pushes back against movement. More resistance means less current when voltage stays the same.