Investigating Electricity Part 1 DSVS Spring 2011 Eighth Grade Lab 2
Lab Set Up You will be using the same kit for the next two labs For the first session, it is suggested you try to get through exercise 5 at least. These labs are more time consuming than they appear. We will skip exercise 4, because it is the same experiment performed during the magnetism lab. Don’t pay too much attention to the handouts. There is a lot of unnecessary information and supplementary activities which will use up time.
1: Building Simple Electric Circuits Have the students hook up a basic circuit. Q: When you connect only one side of the bulb to the battery, does it light? A: No.
1: Building Simple Electric Circuits Add another battery to the circuit. Q: Is the bulb brighter when connected to one battery or two batteries? A: two. Q: What happens when you arrange the batteries with the + and + terminals connected? A: The bulb does not light.
1: Building Simple Electric Circuits Add another bulb to the circuit. Place it in series and in parallel.
2: Circuit Diagrams Teach students to read a circuit diagram.
2: Circuit Diagrams Connect a circuit with three bulbs in series. Q: Unscrew one of the bulbs. What happens? A: All the bulbs go out.
2: Circuit Diagrams Connect a circuit with three bulbs in parallel. Q: Unscrew one of the bulbs. What happens? A: The other bulbs stay on. Additional circuits are suggested in the activity book. If the students are advanced, these would be good for them. If not, they aren’t necessary.
3: Conductors and Insulators Set up the simple circuit as shown. Leave a space for completing the circuit with the trial substances. Some substances won’t clip easily into the alligator clips, the circuit can be completed by just touching the ends. Try several substances and classify them as either conductors or insulators.
5: How to Use and Ammeter Connect the circuit as shown. Make sure students understand the ammeter has to be incorporated into the circuit to measure the current. Q: What is Current? A: the flow of charge This will be very important for the next labs.
Wrapping it Up Clean up Answer Student Questions Discuss the experiments and draw conclusions. Remind students not to forget how to use an ammeter. This will be important next lab.
References These activities and discussion questions are from: “Investigating Electricity” Hubbard Scientific Inc. Chippewa Falls, Wisconsin Training slides and photos Lerin Rutherford