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Trial 3 - Measuring Voltage in a Circuit

In Investigation 1, we found out that two batteries can make a single holiday bulb brighter than one battery. This has to do with voltage, which we can measure with the voltage sensor. Now you are going to measure voltages in your circuit. Refer to Technical Hints to connect the voltage sensor.

Measuring Voltage in a Parallel Circuit

1. Using the voltage sensor, measure the voltage across the battery. Make sure to connect the red wire to the positive (+) side of the battery as shown. Refer to Technical Hints to connect the voltage sensor. Record the voltage.

   ***Missing Image***

   
   
2. Now measure the voltage across each holiday bulb as shown. Record the voltages. Refer to Technical Hints to connect the voltage sensor.

   Bulb 1 Voltage:

   Bulb 2 Voltage:

   
   
3. The voltages across the batteries and the bulbs are shown below. What do you notice about the voltages?

   ***Missing Image***

   
   
4. Get together with another team that measured voltage on a different type of circuit. Does the graph of voltages look the same for each type of circuit? Explain. Be prepared to share your results with the class.
   
   
5. How do the voltages measured compare with the brightness of the holiday bulbs in series and parallel circuits? Be prepared to share your results with the class.
   
   

Measuring Voltage in a Series Circuit

1. Using the voltage sensor, measure the voltage across the battery. Make sure to connect the red wire to the positive (+) side of the battery as shown. Refer to Technical Hints to connect the voltage sensor. Record the voltage.

   ***Missing Image***

   
   
2. Now measure the voltage across each holiday bulb as shown. Record the voltages. Refer to Technical Hints to connect the voltage sensor.

   Bulb 1 Voltage:

   Bulb 2 Voltage:

   
   
3. The voltages across the batteries and the bulbs are shown below. What do you notice about the voltages?

   ***Missing Image***

   
   
4. Get together with another team that measured voltage on a different type of circuit. Does the graph of voltages look the same for each type of circuit? Explain. Be prepared to share your results with the class.
   
   
5. How do the voltages measured compare with the brightness of the holiday bulbs in series and parallel circuits? Be prepared to share your results with the class.