## Introduction: Circuit Tester

Complete a simple circuit to show transformation of energy - chemical energy, to electrical energy, to thermal energy, to light energy!

We use these circuit testers in our fourth grade class as part of our energy unit. That includes our circuit boards. See our Instructable Circuit Board here. The circuit board is great for reinforcing complete circuits and insulators / conductors.

Standards meet for grade levels 3, 4, and 7th

Heat, electrical energy, light, sound and magnetic energy are forms of energy. (3)
Electric circuits require a complete loop of conducting materials through which an electrical energy can be transferred. (4) Electrical energy in circuits can be transformed to other forms of energy, including light, heat, sound and motion. (4S) Electrical energy transfers when an electrical source is connected in a complete electrical circuit to an electrical device. (7)

Electric circuits require a complete loop of conducting materials through which an electrical energy can be transferred. (4)
Electrical conductors are materials through which electricity can flow easily. Electricity introduced to one part of the object spreads to other parts of the object. (4) Electrical insulators are materials through which electricity cannot flow easily. Electricity introduced to one part of the object does not spread to other parts of the object. (4) Electrical conductivity must be explored through testing common materials to determine their conductive properties. (4)

In order for electricity to flow through a circuit, there must be a complete loop through which the electricity can pass. When an electrical device (e.g., lamp, buzzer, motor) is not part of a complete loop, the device will not work. Electric circuits must be introduced in the laboratory by testing different combinations of electrical components. When an electrical device is a part of a complete loop, the electrical energy can be changed into light, sound, heat or magnetic energy. Electrical devices in a working circuit often get warmer. (4) Electrical energy transfers when an electrical source is connected in a complete electrical circuit to an electrical device. (7) An electric circuit exists when an energy source (e.g., battery, generator, solar cell) is connected to an electrical device (e.g., light bulb, motor) in a closed circuit. The energy source transfers energy to charges in the circuit. Charges flow through the circuit. Electric potential is a measure of the potential electrical energy of each charge. (7)

## Step 1: Materials

For this activity each student or group will need

-Scissors
-1.5V Battery

-Wire Stripper

-Electrical Tape

-Old Holiday Lights

## Step 2: Cut and Strip

Using your scissors or wire cutters, cut the Christmas lights as shown.

You will need one wire with a light and one without.

Make sure the one without the light bulb is long.

Take wire strippers and strip the ends of your wires.

## Step 3: Quick Check

Check that the bulb is working by attaching the exposed light bulb wires to the battery.

The light attached to the battery is a circuit. We could stop there, but we need the extra wire for a coming up activity.

## Step 4: Tape Light

Tape one end of the bulb to the battery.

## Step 5: Tape Wire

Using the electrical tape, tape the wire without the bulb to the battery.

Check to see if the wires are connected well to the battery.

## Step 6: Light It Up

Connect the two exposed wires.

Light turns on!

You now have a complete circuit!!!!

## Step 7: Testing Conductivity

Test all kinds of materials to see if the light will come on. If the light turns on, the material is conducting electricity!
Explore with various items, such as pennies, foil, pencils, paperclips, plastic, etc.

When working with students we discuss the dangers of outlets and sticking things into them. We do not want a student putting a tester into a wall outlet. Other then the outlet, we encourage students to try everything they can think of. Braces is an interesting conductor :-) as a student was excited to teach us.

We discuss why some materials allow the light to turn on and others do not. This is a nice way to introduce insulators and conductors.

## Step 8: Tips / Suggestions

We found that the AA batteries work well with younger students instead of the D batteries.

Electrical tape is hard for younger students to work with. Masking tape will work well for this activity.

Remind students to not leave the lights on when not testing. The batteries will deplete and will not work for further exploration.

Participated in the
Classroom Science Contest