You will need the following parts from your kit:1. Breadboard

2. 100 ohm resistor (brown, black, brown, gold)

3. 1 LED (light emitting diode)

4. 1 Potentiometer

5. 9 volt battery lead (connector)

6. 9 volt battery

anodecathode

Flat side Shorter lead

Use this schematic to construct the experiment.

100 ohms

+

-

Flow of current

Flow of current

9 volts

Quick Check:

Your circuit should like this one.

This wire should hang free

Copy and label all the components of the schematic in your notes.

Notice these lines are important

1. Connect the 9 volt battery.

2. Observe the brightness of light from the LED.

3. Turn the shaft on the potentiometer.

4. Observe the change in brightness of light from the LED.

Troubleshooting:

1. If the LED does not light up, check to make sure it is in correctly.

2. Check the battery. Does it have voltage?

3. Are there any breaks in the circuit?

4. Are you using the correct wires on the potentiometer?

1. While completing this experiment, what did you notice about the light from the LED as you changed the potentiometer?

2. Which direction do you twist (clockwise or counter-clockwise) to increase the resistance? Which to decrease?

3. In complete sentences, write what you learned about a potentiometer in a circuit.

Answer these questions

This circuit should light the LED. Answer these questions:

4. Why is the 100 ohm resistor put in this circuit? (Think about the experiment with the LED and resistors)

5. What is a potentiometer?6. The greater the resistance, the ______ the LED

will be. The less the resistance the _____ the LED will be.

7. You may find a potentiometer on your CD-player to adjust the volume from the speakers. Where else can you find potentiometers? List at least 3.