Turtleand Energy

Rung 2 · See the loop

Sweep Ohm's Law

Rebuild the article's 6 V and 12 Ω example, then change one variable at a time.

starter20 minutes0 of 4 stages explored
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A six volt source and twelve ohm resistor connected in one closed loop.
6 V source -> 12 ohm resistor -> return

Knowledge this exercise builds on

Lesson 4: Ohm's Law without formula fear

Practice loop

Try each step before revealing its answer.

The task stays visible. Revealing a numbered answer remembers that stage as explored in this browser. It is not a grade.

ComponentsSee the parts and values before you start.
  • One adjustable DC voltage source, starting at 6 V
  • One adjustable resistor, starting at 12 Ω
  • Wires and one ground reference
PredictCommit to an expected result before running the circuit.

Predict the current for three cases:

6 V and 12 Ω
12 V and 12 Ω
6 V and 24 Ω
Reveal predictionHide prediction
6 V / 12 Ω  = 0.50 A
12 V / 12 Ω = 1.00 A
6 V / 24 Ω  = 0.25 A

Doubling voltage doubles current when resistance stays fixed. Doubling resistance halves current when voltage stays fixed.

BuildWire the circuit yourself from a blank canvas.

Create the 6 V and 12 Ω loop. Edit only one value between observations so cause and effect stay clear.

Show build checkHide build check

Use one closed series loop:

adjustable source -> adjustable resistor -> source return

Keep the ground reference at the return. Restore the starting values before each comparison, then change only voltage or resistance.

MeasureSee what to inspect, compare, and change.

Use the resistor information panel or a scope to record the current in all three cases. Compare the measured ratios before revealing the expected values.

Reveal expected resultHide expected result
6 V / 12 Ω  = 0.50 A
12 V / 12 Ω = 1.00 A
6 V / 24 Ω  = 0.25 A

The 12 V case carries twice the starting current. The 24 Ω case carries half the starting current.

ExplainConnect the observation back to your model.

Explain why doubling voltage doubles current when resistance stays fixed, while doubling resistance halves current when voltage stays fixed.

Reveal explanationHide explanation

Ohm’s Law describes one relationship, not three separate rules. Current rises with voltage and falls with resistance:

I = V / R
Optional referenceReveal reference circuitCompare only after you build. Opening this panel does not contact Falstad.

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Safety boundary

This is a low-voltage educational model.

Do not translate it into mains construction, household wiring, battery-pack work, or real protection settings. Real electrical systems need rated components, proper protection, test equipment, and qualified safety judgment.