Telephone Lines

Telephone Lines

In this game, the students must pass on the message through a human telephone line.

Introduction

A telephone is one of the simplest devices you have in your house. In fact, the telephone connection to your house has not changed in nearly a century. If you had an antique phone from the 1920s, you could connect it to the wall jack in your house and it would work fine.

There are two essential parts to a telephone: the microphone (which you talk into) and the speaker (which you put by your ear).

Inside the microphone is a thin piece of metal called a diaphragm. It vibrates when the vibrations from your voice hit it. As the diaphragm vibrates, it wiggles a magnet to make current flow down the wire.

At the other end is a speaker. A speaker has a permanent magnet and an electromagnet inside it. When electric current pulses flow through the electromagnet, it moves back and forth, attracted and repelled by the permanent magnet. This makes a membrane vibrate, which creates sound. Interference is caused by the tiny imperfections in the wires carrying the electrical pulses.

Objectives