Electricity: Circuits and their Components
The electric cell
Take a close look at an electric cell and its two ends.
Slide a torch's switch one way and the lamp glows; slide it back and it goes off. Open the torch and you find two or more electric cells inside.
Take a cell out and look closely (Activity 3.2). You will see a + sign and a − sign printed on it. One end has a small metal cap sticking out; the other end is a flat metal disc.
Every cell has two terminals:
| End | Terminal |
|---|---|
| the end with the small cap | positive (+) |
| the flat metal disc | negative (−) |
An easy way to remember: the cell wears its cap on the plus end.
A cell is a portable source of electrical energy. Portable means you can carry it anywhere. You can put a cell in your pocket, but you cannot carry a wall socket around with you. That is also why cells are safe for experiments.
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