Introduction to Exciting Electricity
This series is divided into 4 segments, 1 hour each, for a total of four hours.
Purpose: In these activities, students will:
discover electricity flows in a circuit
discover electricity doesn’t work when the circuit is broken
identify insulators and conductors
discern an electrical current creates a magnetic field perpendicular to the current
learn the symbols used to indicate a battery, the resistors, the wires, and the positive and negative sides to the battery
learn to draw a simple electrical schematic (diagram)
recognize how to connect a simple, series and parallel circuit by reading a schematic
Grade:Intermediate students (3-5)
Equipment:Magnetic compass (1/pair)
Wires with alligator clips (7/pair)
Bulb bases (2/pair)
1 large, clear light bulb with filament attached
1 large, clear burned-out light bulb with filament broken
scissors (1/pair)
Materials:6 volt lantern battery (1/pair)
flashlight screw-in bulbs (2/pair) plus replacement bulbs
optional: balloons (1/student)
wax paper 2”x2” square folded into a strip (1/pair)
keys (1/pair)
aluminum foil 2”x2” square folded into a strip (1/pair)
shoe laces made only from cloth and plastic (1/pair)
cloth ½”x2” strip (1/pair)
pencils - wood - sharpened (1/pair)
magnets (2/student)
tape masking or cellophane (1/pair)
coffee straws (10/student)
soda straws (10/student)
optional:buzzers
beepers
switches
diodes
Preparation:Check all batteries and bulbs and replace those that are no longer working. Copy student work sheets, one set per student. It is important that you have replacement bulbs. If the bulbs are not handled carefully, their delicate filaments can break easily.
Divide the following “basic materials” which will be needed for all four experiments and place in individual containers or large zip-lock bags:
Basic Materials Packet includes:
1 battery
2 bulbs
7 wires with alligator clips
2 bulb bases
Supplies needed for Experiment 1:
Basic Materials Packet
large working clear light bulb
large burned-out light bulb
Supplies needed for Experiment 2:
Basic Materials Packet
wax paper 2”x2” square folded into a strip (1/pair)
key (1/pair)
aluminium foil 2”x2” square folded into a strip (1/pair)
shoe laces (1/pair)
cloth ½”x2” strip (1/pair)
pencil (1/pair)
Supplies needed for Experiment 3:
Basic Materials Packet
tape masking or cellophane (1/pair)
magnetic compass
magnets (2/student)
Supplies needed for Experiment 4:
Basic Materials Packet
scissors (1/pair)
coffee straws (10/student)
soda straws (10/student)
tape masking or cellophane (1/pair)
wax paper 2”x2” square folded into a strip (1/pair)
keys (1/pair)
aluminium foil 2”x2” square folded into a strip (1/pair)
shoe laces (1/pair)
pencils (1/pair)
replacement bulbs
optional materials:
buzzers, beepers, switches, diodes
Exciting Electricity Experiment 1
Great Idea: Light the Bulb!
The Complete Circuit
(1 hour)
Preparation:In addition to the Basic Material Packet, for Experiment 1 you will need:
1 large clear light bulb with filament attached
1 large clear burned-out light bulb with filament broken
Optional - 1 balloon per student
Introduction:Electricity is usually invisible. Ask your class to name an example of natural electricity (lightening or the shock created touching a doorknob). Ask your class to name an example of electricity created by humans (light bulbs, TV, walkmans, etc.).
Activity:Optional—Pass out one balloon per student. Ask your students to blow up and tie off their balloon. Ask them to explore static electricity with their balloons. By rubbing the balloon on their hair, clothes or rug, they are charging their balloons with static electricity. When charged, they can make the balloon stick on the wall, make their hair stand on end, or stick to their partner.
Discussion:We are not able to use the electricity in static electricity. The energy from a single lightening bolt can give off 3,750,000,000,000 kilowatts. That is 3.75 trillion kilowatts! The BPA sells 17,664,000 kilowatts of power every hour. If they could harness lightening, 1 bolt would supply power for the entire Pacific Northwest (Oregon, Washington, Idaho, Montana, Northern California and parts of Alaska) for 15 minutes!
There are two types of electricity made by people, AC and DC. AC stands for Alternating Current, the type that your refrigerator uses. DC stands for Direct Current, the types found in batteries. For this series of lessons, we will be using direct current only. Ask your students if they know what types of electricity there are, and an example of each.
Electricity cannot be seen, unless something is hooked up to it that resists it, called a resistor. Ask your students to name a resistor (a light bulb or TV). We can make observations about what is happening to the light bulb, and this can help us guess what the electricity is doing. This type of thinking called “building a model.”
Activity:Instruct your students to turn to their hand out, Exciting Electricity. Read through the instructions, and ask if everyone understands what they need to do.
The first thing to do is to set up the electrical circuit. (Circuit comes from a Latin word that means to go around.) The lights should go on if everything is working. If not, try the following:
Trouble Shooters:
gently tighten the bulbs
check if the circuit is compete
check to see if the filament in the bulb is intact
check the battery
try new light bulbs
check that the clips are clipped to metal
check that 2 clips are not touching each other
You may then either opt to go through the experiments together as a class unit, or instruct your students to work together in their teams. Be sure to encourage discussion, so that the students can brainstorm ideas about what is happening.
When everyone has completed the experiment and worksheet, go through the answers, and discuss the observations, then propose the class discussion question.
Discussion:Ask your class, “What is the “secret” to making the bulbs light?”
Electricity flows like a current of water or wind when there is a complete circuit. To help understand electricity, compare it to water flowing from a high ground to low ground. A more accurate, but not as visual comparison is to air pressure and wind. Air flows from high pressure to low pressure. Electricity flows from the positive terminal (high ground or high pressure) to the negative terminal (low ground).
Circuit means circle. The battery “pushes” the electricity from the positive terminal through the wire, to the bulb, through the filament in the bulb to the wire, through the wire, back to the battery at the negative terminal. When it starts, though, everything moves at once, so the bulbs light simultaneously. If the circuit is broken, then the electricity stops “flowing,” and the bulbs go out.
Ask student to write what they learned about electricity.
Answers to Exciting Electricity Worksheets:
1When did the bulbs light? The light bulb will only light if there is a complete circuit, metal touching metal.
2Did both bulbs light at exactly the same time? Yes, they do.
3Do you believe that both bulbs actually lit at the same time?This is a subjective question, and can be either yes or no.
4What happened? Both light bulbs when out.
5Did both bulbs go out at exactly the same time? Yes, they do.
6Do you believe that both bulbs actually went out at the same time? This is a subjective question, and can be either yes or no.
7What happened? Both light bulbs when out.
8What happened? Both light bulbs stayed out until the metal was touching metal. They did not light until actual contact was made.
9Do you need actual contact before the bulbs will light? Yes.
10Draw a picture of the light bulb in the space provided below. Be sure
to show the metal tip, the glass globe, and the filament.
11Can you think of what the filament does in the light bulb? It completes the circuit, so the electricity can continue to flow through the bulb. It is a resistor, so it makes electricity heat up the very thin wire in the glass globe, and that is what glows to make the light.
12What do you think happens to filament when the light bulb burns out? When the filament is burned-out, the circuit is broken, so electricity cannot flow. The wire cannot heat up without the flow of electricity, so the wire will not glow to produce light.
13List everything that is needed to make the bulb light. Battery, wires, light bulb with an intact filament. Other answers may include metal base for the bulb, metal clips on the wires.
14Write down your thoughts from your final classroom discussion (use the back of this page if you need more room). Your final discussion will determine the answers given, although students may come up with other ideas while doing this part of the lesson.
Exciting Electricity Experiment 1
Great Idea: Light the Bulb!
The Complete Circuit
(1 hour)
Welcome to the exciting world of electricity! In this experiment, you and your partner(s) will figure out what conditions are necessary for electricity to work. You will also begin to learn the basic symbols used to represent electricity.
Before beginning, we need to review your equipment.
Please notice that the top end of the battery has two brass springs. If you look at the cardboard top to the battery, the spring near one corner has a (+). This is the positive end of the battery. The spring in the center has a (-) by it, and This is the negative end of the battery. The springs are called terminals.
All 7 wires should all have alligator clips attached to them.
The round disk is called the bulb base. It will either be all metal, or it will be metal where the bulb is screwed in and have two metal terminals with a plastic or porcelain base.
You should also have two small flashlight bulbs.
Please notify your teacher if anything is missing. Please be very careful with all your materials. The little bulbs are delicate. Handle them with care.
How to set up your equipment for this series of experiments:
Screw each bulb into each bulb base. Do not force it or make it too tight. Find three wires. Connect one end of the wire to the positive battery terminal, and the other to one side of the bulb base. Connect the second wire between the 2 bulb bases. Connect the third wire between the bulb base and the negative battery terminal. See the diagram as you work. You can use that as a guide while connecting all your wires, and your equipment should look like the diagram when you are done.
1When did the bulbs light?______
2Did both bulbs light at exactly the same time?______
3Do you believe that both bulbs actually lit at the same time?
______
Break the loop by disconnecting the wire connected to the battery. You only need to disconnect at one point. Leave the wire connected to the bulb base.
4What happened?
______
5Did both bulbs go out at exactly the same time?______
6Do you believe that both bulbs actually went out at the same time?
______
Reconnect the wire from the battery holder to the bulb base. Disconnect the wire connecting the two bulb bases. You only need to disconnect at one point, and do not need to disconnect from both bulb bases.
7What happened?
______
Slowly bring the clip on the wire to the metal contact point on the bulb base. Carefully watch the distance between the clip and the metal on the base.
8What happened?
______
9Do you need actual contact before the bulbs will light?______
Your teacher has 2 big light bulbs, one working and one burned-out. Go look carefully at them. Do you see the wire inside both light bulbs? That is called a filament. Think about what you had to do to make the bulbs light.
10Draw a picture of the working light bulb in the space provided below. Be sure to show the metal tip, the glass globe, and the filament.
11Can you think of what the filament does in the light bulb?
______
12What do you think happens to filament when the light bulb burns out?
13List everything that is needed to make the bulb light.
______
14Write down your thoughts from your final classroom discussion (use the back of this page if you need more room):
______
Exciting Electricity Experiment 2
Stop and Go!
Insulators and Conductors
(1 hour)
Preparation:In addition to the Basic Material Packet, for Experiment 2 you will need to divide the following materials and place in individual containers or small zip-lock bags:
wax paper 2”x2” square folded into a strip (1/pair)
keys (1/pair)
aluminum foil 2”x2” square folded into a strip (1/pair)
shoe laces (1/pair)
cloth ½”x2” (1/pair)
pencils (1/pair)
Introduction:Some materials allow electricity to flow, and therefore, complete the circuit. These materials are called Conductors. Some materials stop the electricity from flowing, and therefore break the circuit. These materials are called Insulators. Ask your students to define the words conductor and insulator. Ask how these two words could apply to electricity.
Activity:Instruct your students to turn to the hand out, Stop and Go!. Read through the instructions, and ask if everyone understands what they need to do.
The first thing to do is to set up the electrical circuit. (Circuit comes from a Latin word that means to go around.) The lights should go on if everything is working. If not, try the following:
Trouble Shooters:
gently tighten the bulbs
check if the circuit is compete
check to see if the filament in the bulb is intact
check the battery
try new light bulbs
check that the clips are clipped to metal
check that 2 clips are not touching each other
You may then either opt to go through the experiments together as a class unit, or instruct your students to work together in their teams. Be sure to encourage discussion, so that the students can brainstorm ideas about what is happening.
When everyone has completed the experiment and worksheet, go through the answers, and discuss the observations, then propose the class discussion questions.
Discussion:Ask your class, “What is an insulator? What is a conductor?”
An insulator is any material, when joined to the circuit, that prevents the light bulb from lighting (or any other type of resistor from working). It prevents the passage of electricity. “A non-conducting substance or body, as porcelain or glass, used in insulating wires, etc.” Webster's Collegiate Dictionary, 5th Edition.
A conductor is any material, when joined to the circuit, that permits the light bulb to light (or any other type of resister to work). It allows the passage of electricity. “A substance or body capable of readily transmitting electricity, heat, or the like.” Webster's Collegiate Dictionary, 5th Edition.
Ask your class, “What do you need for an electrical circuit? List all the components (parts) and the materials from which they are made. Why is it important that some materials are insulators?”
An electrical circuit needs a power source (battery), wires, with conductors on the inside and insulators on the outside, resistors so we know that electricity is actually flowing (sometimes we can tell because the battery or wires will get hot). Conductors are usually metal, and insulators are usually plastic or glass. If there were no insulators, we would get shocked, and we would not be able to use the electricity. It would be too dangerous. Also, insulators direct the electricity to where we want it to go. Without it, we might never get the light bulb to light, because we could too easily create “short circuit”, or a path around the resistor.
Ask your class, “Why do you think people use electrical schematics?”
A schematic is an abstract drawing that is easy to read. It can tell you how your house is wired. An electrical engineer can design a complex electrical system for the Space Shuttle by using the same symbols. If something doesn’t work, or breaks, it is easy to go back, see what was done, and how to test it.
Answers to Stop and Go Worksheets:
1Did your bulb light? This is to help students trouble shoot before they begin the experiments.
2Students fill out table (answers on next page). Students predictions and answers for “Other” will vary.
Test Object / PredictionInsulator or Conductor / Observation
Lit or not lit / Actual
Insulator or Conductor
Key / lit / conductor
Waxed Paper / not lit / insulator
Aluminum Foil / lit / conductor
Shoe Lace / not lit / insulator
Pencil Wood / not lit / insulator
Pencil “lead” / lit / conductor
Pencil metal band / lit / conductor
Clothing / not lit / insulator
Other
Other
3What do you notice about conductors? (What is something that they all have in common?) Most conductors are made of metal. The pencil “led” is actually made from graphite, which is carbon based, and non metallic. It is only modest conductor compared to the metal band on the pencil.