Lesson 13 of 15
The big picture
Show on a big screenA lamp that will not glow has a reason.
| Idea | Remember | Example |
|---|---|---|
| The loop | The lamp glows only when the path is closed, with no gap. | One wire: dark. Two wires: lit. |
| Switch | A switch opens or closes the gap. ON is closed. OFF is open. | A paper-clip switch. |
| Conductors | A conductor lets electric current through. An insulator does not. | Metal: yes. Rubber: no. |
| Symbols | Every part has a symbol. A drawing made of symbols is a circuit diagram. | Long line and short line: a cell. |
| Battery | Join the + of one cell to the − of the next. Turn one of two cells round, and their pushes cancel. The lamp stays dark. | One cell turned round: dark. |
| One loop | Parts in one loop share one path. Take one out and every lamp goes dark. | Lift one lamp, both go dark. |
| Safety | Use only cells for experiments. Keep your hands dry. Never use a damaged wire. | An adult stays with you. |
| LED | An LED lets current through one way only. It glows only when its long leg meets the + end. | Long leg to +: glows. |
| Two kinds of current | A cell gives direct current, which flows one way. A wall socket gives alternating current, which keeps reversing. | Torch cell: DC. Socket: AC. |
| Dark lamp | A dark lamp has a reason. Check the switch, the lamp, the cell and the wire ends. | A fused lamp stays dark. |
Look for a gap or an insulator. Look for two cells pushing against each other. Look for a broken filament.
Now open Chapter 3 in your NCERT book. You have built, drawn, broken and mended circuits.