Series and parallel circuits
Two bulbs one after another and two bulbs side by side: compare brightness, current and voltage. Click the switch — the circuit is live.
2D
Age 9+15 min
Electricity
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Press “Run”. Bodies move by the laws of physics: gravity, friction, elasticity.
What the experiment shows
On the left the bulbs are in series: the same current flows through both, the voltage is split in half and they glow dimly. On the right they are in parallel: each gets the full voltage and glows brightly.
How to run it
- Press “Run”: moving dots show the current.
- Click the left switch — both bulbs go out together.
- Remove one bulb on the right — the other keeps glowing. And on the left?
Questions to discuss
- Why are household lamps wired in parallel?
- What does the ammeter read with identical bulbs and a 6 V battery?
The science
Ohm’s law: I = U/R. In series the resistances add, the current is the same and the voltages divide: U₁ + U₂ = U. In parallel every branch has the same voltage and the currents add up: I = I₁ + I₂.
Try it at home
Build a circuit from a battery, a bulb holder and wires (with a parent!). Add a second bulb both ways and watch the brightness.
What to change in the editor
- Change the resistance of one bulb.
- Add a voltmeter across a bulb.