Students are briefly introduced to Maxwell's equations and their significance to phenomena associated with electricity and magnetism. Basic concepts such as current, electricity and field lines are covered and reinforced. Through multiple topics and activities, students see how electricity and magnetism are interrelated.
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- Florida: Science
- Investigate and describe some basic forms of energy, including light, heat, sound, electrical, chemical, and mechanical. (Grade 5)  ...show
- Investigate and explain that an electrically-charged object can attract an uncharged object and can either attract or repel another charged object without any contact between the objects. (Grade 5)  ...show
- Investigate and explain that electrical energy can be transformed into heat, light, and sound energy, as well as the energy of motion. (Grade 5)  ...show
- Investigate and illustrate the fact that the flow of electricity requires a closed circuit (a complete loop). (Grade 5)  ...show
- Identify and classify materials that conduct electricity and materials that do not. (Grade 5)  ...show
- International Technology and Engineering Educators Association: Technology
- Standard 6. Students will develop an understanding of the role of society in the development and use of technology. (Grades 0 - 12)  ...show
- Standard 3. Students will develop an understanding of the relationships among technologies and the connections between technology and other fields of study. (Grades 0 - 12)  ...show
- Next Generation Science Standards: Science
- Ask questions about data to determine the factors that affect the strength of electric and magnetic forces. (Grades 6 - 8)  ...show
- Conduct an investigation and evaluate the experimental design to provide evidence that fields exist between objects exerting forces on each other even though the objects are not in contact. (Grades 6 - 8)  ...show
- Explain the interconnections that exist between electricity and magnetism.
- Describe how a changing magnetic field produces current in a loop of wire.
- Determine the factors that affect the strength of electromagnetic forces.
Lesson Background and Concepts for Teachers
- Gauss' law of magnetism shows that an isolated magnetic pole does not exist. All magnets have two poles designated as north and south. A single pole cannot exist in nature apart from its opposite.
- Gauss' law of electricity shows that isolated electric charges do exist. Therefore, the separation and isolation of positive and negative charges allows each to independently exist in nature.
- Ampere's law shows that a current through a wire produces a magnetic field that curls around that wire.
- Faraday's law of induction shows that a changing magnetic flux through a coil of wire induces a current to flow in that wire in order to produce a magnetic flux to oppose the changing magnetic flux.
|AC (alternating current):||In AC, the direction of electron flow constantly changes in direction; this is preferable to DC for home use since it takes less power to transport and is more efficient when producing.|
|Ampere's law:||One of Maxwell's four equations; it states that a flow of electrons, or current, creates a magnetic field that circles around the direction of current.|
|charged:||The characteristic of a particle to be susceptible to any of the basic forces (that is, gravity, electrical, magnetic); a higher charge means a greater susceptibility to the associated force; negatively charged means a reversed reaction to the force (that is, a negatively charged electrical particle moves the opposite direction of a positive particle when subject to the same electrical force).|
|current (or electrical current):||A flow of electrons through a conducting material due to a force; it is similar to water current, which is the flow of water particles due to gravity or some other force.|
|DC (direct current):||In DC, the direction of electron flow is held constant; this is the kind of power that is produced in a battery.|
|electric field:||A set of lines used for visualizing the force around a charged particle; the lines always point from a positively charged particle to a negatively charged particle.|
|electric generator:||A device that converts mechanical energy (such as that coming from wind turbines) to electrical energy.|
|electromagnet:||A temporary magnet created by running a current through a coil of wire that is wrapped in a loop; usually this loop is wound around a piece of metal such as iron or iron compound.|
|electromagnetism:||The sum of all relationships between electricity and magnetism.|
|Faraday's law of induction:||One of Maxwell's four equations; it states that a changing magnetic field induces a current in a wire; this law is the basis for electric generators that are used in every power plant except solar power (that is, hydro, wind, oil, natural gas, nuclear, etc.).|
|field lines:||Imaginary lines used to show direction of force. While most often used in magnetism, they are also used to illustrate electricity and gravity.|
|force:||A push or pull that can cause a change in motion of an object.|
|gravity:||The energy and forces associated with gravitationally charged particles, such as all known matter; unlike electricity and magnetism, gravity is only known to have one charge and all charges attract.|
|Gauss' law of electricity:||One of Maxwell's four equations; it states that particles exist that only contain one kind of electric charge (that is, negative or positive).|
|Gauss' law of magnetism:||One of Maxwell's four equations; it states that particles do not exist that only contain one kind of magnetic charge (that is, south or north).|
|magnetic field:||A set of lines that show the direction of magnetic force; they can be seen by putting iron shavings around a magnet, and by knowing that they always point from the north pole of the magnet to the south pole.|
|magnetic:||Relating to or caused by magnetism; having the properties of a magnet, that is, of attracting iron or steel.|
|magnetism:||The energy and forces associated with magnetically charged particles, such as those found in bar magnets; due to the Earth having a magnetic field that consistently points in the same direction, magnets have for a long time been used in navigation; magnetism is due to the movement of electrically charged particles, such as electrons.|
|Maxwell's equations:||Four equations (Faraday's law, Ampere's law, and two Gauss' laws) that describe the total relationship between electricity and magnetism; the equations are derived through observations in experimentation.|
|solenoid:||A coil of wire used in an electromagnet.|
|voltage:||The rate at which energy is drawn from a source that produces a flow of electricity in a circuit; expressed in volt|
- Whose Field Line Is It Anyway? - Students use bar magnets, paper and iron shavings to reveal the field lines around magnets. They repeat the activity with electromagnets made by wrapping thin wire around a nail and connecting either wire end to a battery. Seeing that the magnetic field induced by electricity is no different than that produced by a bar magnet solidifies the connection between electricity and magnetism.
- The Good, the Bad and the Electromagnet - Students use straw, loose staples, wire, iron nails and batteries to make two versions of electromagnets—one with and one without an iron nail at its core. Testing reveals the importance of an iron core to the magnet's strength.
- What is an electromagnet? Hint: Split the word and go from there. (Answer: An electromagnet is any object that becomes a magnet when electricity is run through it, and stops being a magnet when the electricity is turned off.)
- How do you think that most of the electricity that we use is generated? (Answer: Most electricity is produced by moving a coil of wire and a magnet around each other. Less than 1% of the electricity is presently produced through chemical reactions and solar panels.)
- With a partner, make a list of the factors that might affect the strength of an electromagnet, as pictured in Figure 1.
- The type of coil/wire (i.e. the lower resistance in winding material, the more powerful it will be)
- The number of windings of the coil (i.e. more windings makes more powerful electromagnet)
- Stronger electrical power
- Less leakage fro the power from the windings (i.e. better insulation makes a more powerful magnet)
- Knowing the factors that influence strength of the electromagnet, do some research on the type of wire and insulation one could use to make a strong electromagnet.
 Fowler, Michael. "Historical Beginnings of Theories of Electricity and Magnetism." Posted 1997. Galileo and Einstein, Physics, University of Virginia. Accessed November 30, 2011. (course lecture notes)
 Fitzpatrick, Richard. "Ampère's Circuital Law." Posted July 14, 2007. Electromagnetism and Optics, an introductory course at the University of Texas at Austin. Accessed November 30, 2011.
James Cooper and Mandek Richardson (under the advisement of Patricio Rocha and Tapas K. Das)
© 2013 by 2013 Regents of the University of Colorado; original © 2011 College of Engineering, University of South Florida
STARS GK-12 Program, College of Engineering, University of South Florida
Last modified: June 29, 2015