1. Speaker Foundations of Technology Speaker © 2013 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology Teacher Resource Unit 4 Lesson 4

2. Objective: 1.You will build a simple circuit to observe that a speaker turns electrical energy into sound.

3. You will need the following parts from your kit: 1.Breadboard 2.10 ohms resistor (brown, black, black, gold) 3.Speaker 4.9 volt battery lead 5.9 volt battery

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

5. This circuit will make a speaker make a clicking noise. 1.The speaker has a coil of wires that when an electrical current is applied to it, it makes an electromagnetic field. 2.The speaker has a permanent magnet in it. 3.The electromagnet is attached to a paper cone. 4.When powered, the electromagnet is attracted to the permanent magnet causing the paper cone to mechanically move. 5.A short sound will be heard only when you connect and disconnect the wire from the speaker.

6. 1.Connect the battery to the battery clip. 2.Quickly touch the lead from the battery to the 10 ohm resistor. 3.Do not leave the wire touching the resistor for too long as it will damage the resistor and speaker. Troubleshooting: 1.Check the battery. Does it have voltage? 2.Are there any breaks in the circuit? 3.Is the speaker damaged?

7. By completing this experiment, you should have heard a clicking sound from the speaker as you touched the wire from the battery to the resistor. In complete sentences, write what you learned about a speaker in a circuit.