Labs / Physics
Circuits
Click the switch to close the loop and the charges start moving. Turn up the battery voltage or dial the resistance down and the current speeds up, so the bulbs burn brighter — exactly what Ohm’s law, I = V / R, predicts. Then swap the two bulbs between series and parallel and see how the wiring changes everything.
V 6.0 VI total 0.75 Aper bulb 0.75 AQ 0.00 C
What to try
- Switch from series to parallel at the same voltage and resistance. Why does the total current jump so much?
- In series, what happens to both bulbs if you double the resistance? Does one bulb dim more than the other?
- The charge counter Q keeps climbing while the switch is closed. What does the current tell you about how fast charge is delivered?
- Can you find a voltage and resistance where a single parallel bulb glows as brightly as a series bulb does? What does that reveal about the current each one gets?
- Open the switch mid-flow. Where does the current go, and why do both bulbs go dark at exactly the same instant?