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Home/Electricity & Magnetism/Circuit Builder

Circuit Builder

A sandbox for DC circuits: batteries, resistors, bulbs, and switches. Current paths update as you connect elements, supporting intuition for series, parallel, and Ohm’s law.

Who it's for: First circuits courses; labs before breadboarding.

Key terms

  • Ohm’s law
  • series
  • parallel
  • current
  • voltage
  • resistance

Palette (drag to slot row below)

Series loop only: empty slot = open circuit. Use at least one battery and close the loop with wires.

Battery

9 V

Slots — drop here or click after selecting part

slot 1
slot 2
slot 3
slot 4
slot 5
slot 6

Shortcuts

  • •Drag a part onto a slot number
  • •Or select part + click slot

Measured values

EMF (batteries)9.00V
R total162.1Ω
I55.52mA

How it works

A toy series-loop builder: place components into six slots around a schematic path. Empty slot breaks the loop. Current follows I = ΣV/ΣR when every series switch is closed and the path is complete.

Key equations

I = EMF / R_total (ideal wires; bulb & resistor are R)

Frequently asked questions

Is this a full SPICE simulation?
The goal is pedagogy: simplified ideal models that run in the browser. Quantitative behavior is illustrative; always verify critical designs with appropriate engineering tools.