Teacher Pages
Teacher Pages

ELECTRICITY

California State Standards addresed Grade four Physical Sciences Sub Sections: 1. Electricity and magnetism are related effects that have many useful applications in everyday life. As a basis for understanding this concept: c. Students know electric currents produce magnetic fields and know how to build a simple electromagnet. d. Students know the role of electromagnets in the construction of electric motors, electric generators, and simple devices, such as doorbells and earphones. e. Students know electrically charged objects attract or repel each other. f. Students know that magnets have two poles (north and south) and that like poles repel each other while unlike poles attract each other.

Grade Nine - Twelve: Electric and Magnetic Phenomena Sub Sections: Electric and Magnetic Phenomena 5. Electric and magnetic phenomena are related and have many practical applications. As a basis for understanding this concept: e. Students know charged particles are sources of electric fields and are subject to the forces of the electric fields from other charges. f. Students know magnetic materials and electric currents (moving electric charges) are sources of magnetic fields and are subject to forces arising from the magnetic fields of other sources. g. Students know how to determine the direction of a magnetic field produced by a current flowing in a straight wire or in a coil. h. Students know changing magnetic fields produce electric fields, thereby inducing currents in nearby conductors. j.* Students know electric and magnetic fields contain energy and act as vector force fields.

 

Electricity and magnetism are very closely related. The exhibits on this Pathway let you see, hear, and feel what happens when magnets and electricity go to work on each other. Try to find the magnets and the electric current in each of these exhibits. If you have any questions or problems, ask an orange-jacketed Explainer for help.

CIRCLES OF MAGNETISM I
Associated Snack
CIRCLES OF MAGNETISM

The thick copper rod running through the table top is really a giant wire. Press the button in the table top to send an electric current through this wire. Watch the way the compass needles move.

GENERATOR EFFECT

Pull the handle back and forth very quickly and the light bulb will light up. You're making electric power for this bulb with nothing more than a coil of wire and large magnets.

MAGNETIC SUCTION
Associated Snack
Magnetic Suction

Plug in the yellow plug and turn the voltage all the way up. Put the iron bar into the mouth of the coil and feel the magnetic force pull the bar in.

Unplug the yellow plug. Is there any magnetic force now?
__yes __no

Try to find a coil and an iron rod in the doorbell and in the pinball flipper.

MOTOR EFFECT
Associated Snack
Motor Effect

Step on the floor mat to send an electric current through the thick black wire. Watch the wire fly up in the air. Try to push it down; you may be surprised at how hard the green and red magnets force the wire upwards!

GIANT METER

Meters measure things. This GIANT METER uses a coil and a magnet to measure the flow of electricity. Turn the knob to make current flow through the coil. This current turns the coil into a magnet, and pushes the magnetized meter needle to one side.

DAISY DYNO

Hold the tip of the wire right at the edge of the metal disk, beneath the magnet. Does the disk spin? __yes __no

Now hold the wire right near the center of the disk. Does it spin? __yes __no

STRIPPED-DOWN MOTOR
Associated Snack
Stripped Down Motor

Turn on the switch by the battery and watch the copper wires spin!

Try to follow the path of the electric current with your finger. It starts out at the negative side of the battery (marked &emdash;) and passes through the whole motor to get to the positive (+) side. On the way, it goes through the copper plate, a thick L shaped loop of wire, the copper plate again, and the switch.

If you have a keyring, see if it sticks to the large orange magnet.