ELECTRICITY TRAVELING EXHIBIT K-12 EDUCATOR S GUIDE

Transcription

1 ELECTRICITY TRAVELING EXHIBIT K-12 EDUCATOR S GUIDE

2 What is static electricity? What is current electricity? How do we use electricity? The Electricity exhibit invites you and your students to consider these questions and find answers. During your visit, students will: Interact with devices that show how electricity works. Learn about natural sources of electricity. Explore forces of electromagnetism. After your visit, students will: Understand how charged particles interact. Know the difference between static and current. Appreciate applications and uses of electricity.

3 EXHIBIT OVERVIEW The Electricity exhibit features four major themes: static electricity, current electricity, electromagnetism, and the applications and uses of electricity. Each section is described more fully below. As you enter the exhibit, you are asked to consider that electricity has always existed in nature. It wasn t until the eighteenth century, that scientists, including Benjamin Franklin, began to understand the basic principles of natural electricity. Franklin suspected, and proved, that lightning is a stream of electrically-charged particles. Students are next asked to explore static electricity where they learn about static charge and that, while lightning can be terrifying, it is actually a fairly simple phenomenon. Triboelectricity The hard part is controlling those charged particles. In the current electricity section, students discover how electricity flows. The content in the electromagnetism devices helps students see how magnetic materials help to generate and regulate electrical charges. Finally, with a safe, steady flow of current electricity, the applications and uses of electricity become endless. Encourage your students to discuss the many ways they use electricity every day. Help them see the relevance of the exhibit content to their everyday lives. Electrostatic Generator

4 STATIC ELECTRICITY Electrostatic Generator Build up a static electricity charge with a wool cloth and plastic cylinder. Then, feel the electric fire as you hold your finger an inch away from the brass sphere. Triboelectricity Create charged particles by rubbing the plastic top of the box with wool or other materials. The charged plastic induces a charge in the loose materials inside the box which are then attracted to the top. Plasma Tube Create lightning in a tube! The tube is filled with a mixture of gases that reacts with electricity from the central electrode to produce plasma lightning. The lightning spirals outward in tendrils of purple, pink, and blue. Jumping Ring CURRENT ELECTRICITY Jumping Ring Push a button causing electricity to be discharged, repelling a ring atop the device. Jacob s Ladder Voltage passes between two rods in this interactive. Trigger the transformer to increase voltage between the alternating current to the extent that the air around it becomes ionized. An arc forms and rises as the surrounding air is heated. Forces on Conductors How do flowing currents relate to magnetic fields? Send a large current at a low voltage through two copper poles, and watch the poles react by pushing or pulling against each other, depending on the direction of the current. Basic Batteries Become a battery by placing your hands on two of the four metal plates. Your body becomes the electrolyte connecting the two electrodes, causing movement in a meter. Then, experiment between four plates to see which pairs of electrodes complete the circuit. Tangent Galvanometer Make the Lights Go On Make a simple transformer. When electricity in a coil creates a changing magnetic field it creates electricity in a second coil. Lift a coil until the lights turn on. Electricity is being transferred from the top coil to the bottom one.

5 ELECTROMAGNETISM Tangent Galvanometer This instrument uses the earth s magnetic polarization to show the electric flow passing through its coils. See how electricity can be used to manipulate the direction of a compass needle. Solenoid Create a magnetic field by moving a magnetic rod through a copper spool. This pools enough energy to create a magnetic field strong enough to hold the heavy rod up. Reciprocating Motor Eddy Current Brake Turn a crank and create a magnetic field. In the middle is a moving disc which is the conductor for the field. Then, step on a pedal. The resulting resistance makes it very difficult for the disc to rotate in any direction. Magical Mystery Magnetic Motion What is causing a magnet to move? A rotating magnet hidden below causes the magnet above to be set into motion. APPLICATIONS & USES OF ELECTRICITY Spark Transmitter Listen and watch while pressing a telegraph key to observe the sounds and sparks made by the earliest wireless transmitters. Reciprocating Motor Try to get the flywheel turning by cranking the wheel and using the manual button. Then, connect the motor to the power supply through the commutator. This turns the coils on and off at just the right time to keep the motor running. How a Telegraph Works Telegraphs use open and closed circuits to energize electromagnets in sounders at a receiving end. Resistance In Wires Morse Code Morse code is an alphabet developed for the telegraph. Send messages between two machines and experiment with a telegraph key hooked to a readout of the resulting messages.

6 Morse Code Resistance In Wires Illuminate three bulbs and observe the difference in brightness due to each filament s resistance. Video: How Does Electricity Get Into Your Home? Learn how electricity travels through the electrical grid to the outlet in your home. Electrical Safety Dioramas What happens if you aren t careful around electricity? Take a lighthearted look at the dangers of electricity in these interactive dioramas and learn about the dangers that can occur if you aren t careful.

7 TRY THIS! The Electricity exhibit offers several opportunities to learn about static electricity. For Younger Students For years children at birthday parties have played with static electricity whether they realized it or not. Bring this fun exercise to your classroom with the following simple experiment that is good for all ages. Supplies: Latex balloons (oblong shape is better than round) one for each two students To Do: On a cool, dry day inflate the balloon and tie it closed. Rub it on a rug or sweater. Bring the balloon close to a student s hair. What happens? The hair rises to meet the balloon. Note that fine straight hair is most easily lifted. The effect may be harder to see with thicker, curlier hair. By rubbing the balloon, you electrically charged it. The hair rises toward the balloon because of that charge. Students can take turns trying this with a partner s hair and with the hair on their own forearms. The electrical charge is also strong enough to hold the balloon against the wall for a short time. Try it and see how long the balloon will stay.

8 TRY THIS! For Older Students Older students can make lightning following these simple steps. The build-up of static energy is released suddenly as a lightning strike. Supplies: Styrofoam dinner plate Disposable aluminum pie pan (thin enough to puncture with a tack) Thumbtack New pencil with new eraser Wool sock, glove, or piece of fabric To Do: Puncture the bottom of the pie pan so that the tack is sticking up through the center. Attach the pencil to the tack by pushing into the eraser, making a handle for the pie pan. Flip the styrofoam plate so that the bottom becomes the top surface. Rub that top surface hard and fast for a minute the more energy you put into it, the better the effect will be. After a minute, the top surface should be coated with charged particles. Set the wool aside and pick up the pie pan by its pencil handle. Slowly lower it into position atop the plate s charged surface. Now, touch the edge of the pie pan to see how a build-up of static charge can be conducted through metal and released into you! To repeat the effect, simply rub the styrofoam plate again to build up more charge. Note: If you can darken the room, the sparks should be readily visible when they are released from the charged metal surface.

9 CURRICULAR STANDARDS An exploration of the Electricity exhibit can help students achieve learning objectives as called for by national standards. Next Generation Science Standards 4: Energy MS: Forces and Interactions MS: Energy MS: Waves and Electromagnetic Radiation HS: Forces and Interactions HS: Energy HS: Waves and Electromagnetic Radiation National Science Education Standards K-4 B: Physical Science K-4 G: History & Nature of Science 5-8 B: Physical Science 5-8 G: History & Nature of Science 9-12 B: Physical Science 9-12 G: History & Nature of Science Benchmarks for Science Literacy 4. The Physical Setting 4g. Forces of Nature Common Core English Language Arts K-5: Reading Informational Text 6-12: Literacy in Science & Technical Subjects Common Core Mathematics K-12: Measurement & Data Magical Mystery Magnetic Motion

10 An Educational Product of THE FRANKLIN INSTITUTE The Franklin Institute 222 North 20th Street Philadelphia, Pennsylvania