How a Speaker Works

Take Inventory of your Parts You will need the following parts from your kit: Breadboard 10 ohms resistor (brown, black, black, gold) Speaker 9 volt battery lead 9 volt battery

Use this schematic to construct the experiment. Build the Circuit Use this schematic to construct the experiment. + 9 volts - 10 ohm resistor Quick Check: Your circuit should like this one.

Do the Experiment Connect the battery to the battery clip. Quickly touch the lead from the battery to the 10 ohm resistor. Do not leave the wire touching the resistor for too long as it will damage the resistor and speaker. Try touching the wire quickly, very quickly, very very quickly, repeatedly. Does it change the sound? Troubleshooting: Check the battery. Does it have voltage? Are there any breaks in the circuit? Is the speaker damaged?

The Theory: The speaker has a coil of wires that when an electrical current is applied to it, it makes an electromagnetic field. The speaker has a permanent magnet in it. The electromagnet is attached to a paper cone. When powered, the electromagnet is attracted to the permanent magnet causing the paper cone to mechanically move. The paper cone moves the air.

Observations: What did you learn? What did you observe? In complete sentences, write what you learned about a speaker in a circuit.