Make a Simple Electric Device

Electricity flows through a circuit — a complete loop of conducting materials. When the loop is unbroken (closed), electricity flows and a device like a bulb can light up. When the loop is broken (open), electricity cannot flow and the device stops working. Understanding circuits lets us build useful electric devices.

The Four Circuit Components

• Battery — the source of electrical energy; provides the push (voltage).
• Wire — the conductor that carries electricity around the circuit.
• Bulb (or buzzer) — converts electrical energy into light (or sound).
• Switch — opens or closes the circuit to control the flow of electricity.

Open vs Closed Circuit

• Closed circuit — all components are connected in a complete loop; current flows; bulb is ON.
• Open circuit — there is a gap or a switch is open; current stops; bulb is OFF.

Building Your Device

1. Gather: a 1.5V battery, two wires with crocodile clips, a small bulb.
2. Connect one wire from the positive (+) end of the battery to the bulb.
3. Connect a second wire from the bulb back to the negative (−) end of the battery.
4. If the bulb lights, the circuit is closed. Well done!
5. Add a switch: cut one wire and connect the two ends to a switch.