Turtleand Energy

Rung 3 · See the loop

Divide voltage in series

Use two series resistors to see shared current and proportional voltage drops.

foundation25 minutes0 of 4 stages explored
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A nine volt source feeding a one kiloohm and two kiloohm resistor in series with a measurable midpoint.
9 V source -> 1 kiloohm resistor -> midpoint -> 2 kiloohm resistor -> ground

Knowledge this exercise builds on

Lesson 4: Ohm's Law without formula fear

Practice loop

Try each step before revealing its answer.

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ComponentsSee the parts and values before you start.
  • One 9 V DC voltage source
  • One 1 kΩ resistor
  • One 2 kΩ resistor
  • One midpoint probe and one ground reference
PredictCommit to an expected result before running the circuit.

Predict the total resistance, loop current, voltage across each resistor, and midpoint voltage relative to ground.

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The series resistance is 3 kΩ, so the loop current is 3 mA. The 1 kΩ resistor drops 3 V, the 2 kΩ resistor drops 6 V, and the midpoint is 6 V above ground.

BuildWire the circuit yourself from a blank canvas.

Connect the 1 kΩ resistor above the midpoint and the 2 kΩ resistor between the midpoint and ground.

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The path should be:

9 V source -> 1 kΩ -> midpoint -> 2 kΩ -> ground

Both resistors must share the same single current path. Place the midpoint probe at their connection.

MeasureSee what to inspect, compare, and change.

Measure the loop current, each resistor drop, and the midpoint voltage relative to ground. Check whether the two drops add back to the source voltage.

Reveal expected resultHide expected result
loop current  -> 3 mA
1 kΩ resistor -> 3 V
2 kΩ resistor -> 6 V
midpoint      -> 6 V above ground

The drops add to the 9 V supplied by the source.

ExplainConnect the observation back to your model.

Explain why both resistors carry the same current but do not receive the same voltage drop.

Reveal explanationHide explanation

Series components share one current path, so both resistors carry 3 mA. Each drop is V = IR, so the 2 kΩ resistor drops twice as much voltage as the 1 kΩ resistor.

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.