Resistors, Potentiometers, and Reading Color Codes
Controlling current with resistance
What a resistor does
A resistor limits current, divides voltage, and helps protect components from damage.
Potentiometers
A potentiometer is a variable resistor, often used as a knob or slider to change circuit behavior.
Resistance units
Resistance is measured in ohms, written as .
Color codes
Many resistors use colored bands to show their value. The bands encode digits and a multiplier.
Beginner note
You do not need to memorize every color immediately. Start by learning how the code works and practice with a chart.
What unit is used for resistance?
Resistance is measured in ohms.
Correct answer: Ohm
What is a potentiometer?
A potentiometer lets you change resistance manually.
Correct answer: a variable resistor
Using a resistor safely
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1
Step 1: Identify the needed resistance value.
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2
Step 2: Choose a resistor with an appropriate power rating.
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Step 3: Place it in the circuit where current control is needed.
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Step 4: Test the circuit and make adjustments if necessary.
Common resistor roles
| Role | Effect |
|---|---|
| Current limiting | Reduces the flow of charge |
| Voltage division | Creates a smaller output voltage |
| Pull-up or pull-down | Sets a default logic level |
A resistor is mainly used to do what?
Resistors are used to limit current and shape voltage.
Correct answer: Limit current