S3.10.3 For the adult
Series and parallel circuits
Why does one light going out not put all the lights in a house out?
What this chapter teaches
In a series circuit the parts share one loop and the push, so bulbs are dim and one gap puts all out. In a parallel circuit each branch is joined across the cell and gets the full push, which is why houses are wired this way.
Three questions to ask
There is no one right wording. Listen for the idea.
- What happens to a bulb in a parallel circuit when another bulb is switched off?
- Why are two bulbs in series dimmer than one bulb alone?
- Why does a cell run down sooner with bulbs in parallel?
After the chapter, the learner can
- Build a series circuit and a parallel circuit with two bulbs
- Explain why the lights in a house are wired in parallel
What they copy into their notebook
Series: one loop, the same current everywhere, and one gap puts all out. Parallel: each branch has the full push, and the cell gives more. Houses are parallel.