Learn / Circuits / Boost / Dim a light with a variable resistor
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INTERMEDIATE
Ages 8+
5:05
Dim a light with a variable resistor
Put a resistor in the path and the light dims. The resistor has no plus or minus — connect it either way and see why direction doesn't matter here.
VIDEO · exercise walkthrough · chapters: parts · build · test · why
Blocks you need
Battery · LED · Resistor · Dimmer · 3 wires
You'll understand
ResistanceCurrent flowBrightness controlNon-polar components
Steps
1Build the basic battery → LED loop from exercise one.
2Break the loop and snap the resistor into the line — either way round works.
3Watch the LED dim. Swap in the dimmer block and turn it slowly.
4Try the buzzer instead of the LED: resistance turns loudness down too.