Here’s a step-by-step guide to building an Earthquake Alarm Working Model using a buzzer, wire, GI wire, 9V battery, cardboard, and color paper.

Materials Required
- Buzzer (3-12V)
- 9V Battery and Battery Connector
- GI Wire (thin galvanized iron wire)
- Electrical Wires (for connections)
- Cardboard (for the base and structure)
- Color Paper (for decoration and labeling)
- Fevicol adhesive or glue
- Scissors and tape
- Switch (optional, to control the circuit)
How It Works
The earthquake alarm detects ground shaking through a pendulum mechanism. A GI wire loop acts as a switch: When the loop touches a freely hanging pendulum, the circuit completes, triggering the buzzer, simulating an earthquake alert.
Step-by-Step Instructions
Step 1: Prepare the Cardboard Structure
- Base and Frame:
- Cut a square or rectangular base from cardboard (approx. 20 cm x 15 cm).
- Create a vertical stand (frame) to hold the pendulum. You can cut two strips of cardboard and glue them upright at the edges of the base.
- Pendulum Setup:
- Cut a 10-12 cm length of GI wire and shape it into a small hanging pendulum (like a free-swinging needle or hook).
- Attach the pendulum to the top of the cardboard frame so it can swing freely.
Step 2: Create the Switch Mechanism
- Wire Loop:
- Shape another piece of GI wire into a circular loop and attach it to the base (just below the pendulum).
- Position the loop very close to the hanging pendulum—but not touching it. This gap ensures that slight movement completes the circuit.
Step 3: Connect the Buzzer Circuit
- Wiring:
- Connect one wire of the buzzer to the positive terminal of the 9V battery.
- Attach the other wire of the buzzer to one end of the GI wire pendulum.
- Now, connect the wire loop to the negative terminal of the battery (using the battery connector).
- Optionally, add a switch between the buzzer and the battery to control the circuit.
- Test the Circuit:
- When the pendulum touches the wire loop, the circuit completes, and the buzzer will sound.
Step 4: Final Assembly and Decoration
Secure the Parts:
- Use tape or glue to hold the battery, buzzer, and wires in place on the cardboard base.
- Make sure the pendulum swings freely and aligns correctly with the loop.
- Decorate with Color Paper:
- Cover the cardboard with color paper for a neat look.
- Add labels such as “Pendulum,” “Buzzer,” “Battery,” and “Earthquake Alarm.”
Step 5: Testing the Model
Gently shake the base to simulate an earthquake.
- If the pendulum touches the wire loop, the buzzer will ring, indicating an earthquake.
Troubleshooting Tips
- Pendulum not touching the loop: Adjust the position of the GI wire loop or shorten the gap.
- Buzzer not working: Check all connections and ensure the battery is charged.
- Too sensitive or not sensitive enough: Adjust the swing of the pendulum or the distance between the pendulum and loop.
This earthquake alarm working model is simple yet effective for school science exhibitions, demonstrating basic electrical circuits and the concept of alarms.