P30+Forces+&+Fields

The design and analysis of currents flowing in series and parallel circuits of resistors and capacitors is examined in this video. Video (29 minutes)
 * == //GO1// Students will explain the behaviour of electric charges, using the laws that govern electrical interactions. == || ==//GO2// Students will describe electrical phenomena, using the electric field theory.  == || ==//GO3// Students will explain how the properties of electric and magnetic fields are applied in numerous devices.  == ||
 * Electric Circuits (Series: The Mechanical Universe...and Beyond)

Kirchhoff's Laws In a circuit, total current is conserved, total energy is conserved, and the total rise in voltage equals the total drops in voltage around the circuit. <span style="display: block; font-family: Arial,Helvetica,sans-serif;">Video (3 minutes)

<span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">Ohm's Law <span style="display: block; font-family: Arial,Helvetica,sans-serif;"> The voltaic pile is used to discover electromagnetism. This, in turn, leads to Thomas Edison's first electric lamp, and his perfection of the telegraph. Problems with the telegraph were rectified by the rediscovery of Ohm's law. <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="display: block; font-family: Arial,Helvetica,sans-serif;">Video (4 minutes)

<span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Arial,Helvetica,sans-serif; font-size: 12px; text-decoration: none;">Power <span style="display: block; font-family: Arial,Helvetica,sans-serif;"> In some applications, the heat produced by resistance is used to produce light; in other applications, heat represents wasted energy. Power is derived and defined. Using Ohm's law, several ways to calculate power are shown. Also, the watt is defined and some comparative analogies are made with water power. <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="display: block; font-family: Arial,Helvetica,sans-serif;">Video (3 minutes)

<span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Arial,Helvetica,sans-serif; font-size: 12px; text-decoration: none;">Resistance <span style="display: block; font-family: Arial,Helvetica,sans-serif;"> All the factors that lead to electrical resistance are illustrated using an analogy to water pipes. Series resistance and parallel resistance are described based on these factors. <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="display: block; font-family: Arial,Helvetica,sans-serif;">Video (3 minutes)

<span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">Simple Circuit <span style="display: block; font-family: Arial,Helvetica,sans-serif;"> Using a simple circuit, the flow of electrons is measured in amperes. The unit for electrical current is derived and illustrated with animations. <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="display: block; font-family: Arial,Helvetica,sans-serif;">Video (1 minute)

<span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">The Nature of Electrical Resistance <span style="display: block; font-family: Arial,Helvetica,sans-serif;"> Imperfections in the crystal structure of a metal produce resistance, just as viscosity in a liquid creates resistance. As a result, electron flow is uniform and the energy lost as the electrons move is released as heat. <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="display: block; font-family: Arial,Helvetica,sans-serif;">Video (3 minutes)

<span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">Charge Launcher <span style="display: block; font-family: Arial,Helvetica,sans-serif;"> This ExploreLearning Gizmo allows students to simulate the launch of a charged particle into a chamber and to influence the path of the moving particle.Web

<span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">Coulomb's Law <span style="display: block; font-family: Arial,Helvetica,sans-serif;"> In this video, the evolution of Coulomb's law is described. Starting with Benjamin Franklin's idea that electric charge caused electric force, Charles Coulomb found the mathematical relationship between charge and force now known as Coulomb's law. Animations are provided to show how repulsive and attractive forces are created among positive and negative charges. A description of the vector nature for electric forces is included. <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="display: block; font-family: Arial,Helvetica,sans-serif;">Video (3 minutes)

<span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Arial,Helvetica,sans-serif; font-size: 12px;">Electric Field Dipole <span style="display: block; font-family: Arial,Helvetica,sans-serif;"> Simulate the electric field created by two point charges from arbitrary test points, to produce a graphical display of the electric field lines through these points. <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="display: block; font-family: Arial,Helvetica,sans-serif;">Web || <span style="background-color: #c5eafc; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Electric Field Point Charge <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">Simulate the electric field created by a point charge from arbitrary test points, to produce a graphical display of the electric field lines through these points. Web/Video <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; text-align: left;"> <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px;"> Energy of Vector Fields This video defines fields by the line integral and flux. The equations for energy densities in both electric fields and magnetic fields are described.Video (3 minutes) Flux Calculus This video presents a mathematical (calculus) description of the electric flux and magnetic flux.Video (1 minute) Flux Defined as Flow Rate Flux is defined as the total amount of water passing through an element of area in a given amount of time (mathematically derived to be the rate of flow). The mathematical expression of flux is applied to electric flux and magnetic flux. Vector dot products are used.Video (2 minutes) Flux Out of a Closed Surface This video describes a fundamental difference between the types of flux. Water and magnetic flux radiating out from a closed surface are always matched by flux going back into the surface. This is not true for electric and light sources where flux only radiates outward from a point in space.Video (3 minutes) Inverse Square Law Explore the inverse square law as it applies to gravitational and electric fields. Web/Video The Electric Field: Coulomb's Law A test charge is moved around various charged objects and the direction of the force acting on the test charge is illustrated. The pattern of forces exists with or without the presence of a test charge, and this field can be expressed mathematically by Coulomb's law. The electric field pattern created by a single charge, two opposite charges, two like charges, and a multiple array of charges is described using animation. The mathematical nature of the electric field is summarized as E = kq/r² and F = qE.Video (2 minutes) Vector Fields and Hydrodynamics (Series: The Mechanical Universe...and Beyond) This video explores the properties of electric fields, magnetic fields, and hydrological fields.Video (29 minutes) Vector Nature of Fields Water flow has velocity at each point in time and space; therefore, it is a vector quantity that can be compared to the electric and magnetic fields. All three are vector patterns in space and can be described mathematically.Video (2 minutes) <span style="background-color: #c5eafc; color: #006497; font-family: Arial,Helvetica,sans-serif; font-size: 12px; text-decoration: none;"> Water and Magnetism - Vortex Flow <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px;"> Water circulation leads to vortex flow. In the case of water flow, angular momentum is conserved, which leads to the formation of a stable vortex. Magnetism is based on the same principle. By replacing water circulation with charge circulation, a stable magnetic vortex is created.Video (5 minutes) Electricity - Introduction The word "electricity" has been given several different meanings. Benjamin Franklin studied the effects of electricity and incorrectly called it a type of fluid. It is better to think of an electrical force as the attraction between positive and negative charges. Video (3 minutes) Examples of Electrical Forces Electrical forces bind atoms and molecules into liquids and solids. Electrical forces operate in molecular compounds, ionic compounds (e.g. table salt), and metals (e.g. metal springs). The intermolecular electrical forces of attraction are used to explain friction and viscosity.Video (2 minutes) Franklin and the Electric Fluid In this video, Benjamin Franklin’s study of electricity is described. Franklin investigated the “electric fluid” and how an excess or shortage of this fluid gives rise to electric charge.Video (2 minutes) Fundamental Forces (Series: The Mechanical Universe) A variety of phenomena in the universe can be described by four forces. Two nuclear forces (strong and weak) exist within the atomic nucleus. The fundamental force of gravity ranges across the universe. Electricity, the fourth fundamental force, binds the atoms of all matter.Video (29 minutes) Induced Charge Separation An animation is used to show how a charged object, approaching a conductor, will cause charge separation in the conductor.Video (1 minute) Static Electricity (Series: The Mechanical Universe...and Beyond) This video discusses Coulomb's law and the principles of static electricity.Video (29 minutes) <span style="background-color: #fdfef5; font-family: Arial,Helvetica,sans-serif; text-align: left;"> The Atomic Structure of Metals and Conductivity Basic atomic structure is defined including the proton, neutron, and electron. Neutral atoms and charged ions are also defined. Metals are used to describe the electric nature of the atom and the function of conductivity. Animations of the crystal lattice and metallic bonding are used to show how conductivity occurs. Video (4 minutes) The Electroscope Animation is used to show how charge separation and conductivity can cause the movement of the leaves in an electroscope. An animation of how grounding will affect a charged electroscope is also included in this video. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px;"> Video (2 minutes) The Leyden Jar This video describes the Leyden Jar as a device used to store electric charge. An animation is provided explaining how the device works. Video (1 minute) The Tandem Van de Graaff Accelerator This video explains how a tandem Van de Graaff generator is used to supply the charge that makes a particle accelerator work. Video (2 minutes) Charging by Induction A charged object approaches a metal object that is grounded. This allows the movement of charge. The Wimshurst generator functions on this principle. A demonstration of its operation is provided.Video (2 minutes) Induced Charge Separation An animation is used to show how a charged object, approaching a conductor, will cause charge separation in the conductor. Video (1 minute) Static Electricity (Series: The Mechanical Universe...and Beyond) This video discusses Coulomb's law and the principles of static electricity. Video (29 minutes) <span style="font-family: Arial,Helvetica,sans-serif;"> The Atomic Structure of Metals and Conductivity Basic atomic structure is defined including the proton, neutron, and electron. Neutral atoms and charged ions are also defined. Metals are used to describe the electric nature of the atom and the function of conductivity. Animations of the crystal lattice and metallic bonding are used to show how conductivity occurs. Video (4 minutes) <span style="background-color: #c5eafc; color: #006497; display: block; font-size: 12px; text-decoration: none;">The Van de Graaff and Wimshurst Generators This video provides a demonstration of the Van de Graaff generator and the Wimshurst generator. Video (2 minutes) Charging by Friction (Van de Graaff) <span style="display: block; font-family: Arial,Helvetica,sans-serif;"> This video describes how a spinning insulator, such as the Van de Graaff generator, can build up static charge.Video (2 minutes) Induced Charge Separation An animation is used to show how a charged object, approaching a conductor, will cause charge separation in the conductor.Video (1 minute) Charge Launcher This ExploreLearning Gizmo allows students to simulate the launch of a charged particle into a chamber and to influence the path of the moving particle. Web Coulomb Force In this ExploreLearning Gizmo, users investigate forces due to electrical charges. Fixed proton and electron charges may be placed on a two-dimensional grid before firing a moving proton charge into the field. The velocity of the charge is adjustable and is acted on by the Coulomb forces.Web Pith Ball Lab This ExploreLearning Gizmo allows the user to investigate the relationship between electrostatic force and gravitational force. Pith balls with positive, negative, or no electrical charge are suspended from strings. The charge and mass of the balls, as well as the length of the string may be adjusted. Resultant changes in ball location may be measured, and force vectors and magnitudes analyzed. Web <span style="font-family: Arial,Helvetica,sans-serif;"> <span style="background-color: #c5eafc; color: #006497; display: block; font-size: 12px; text-decoration: none;">Coulomb Force (Static) In this ExploreLearning Gizmo, users investigate the relationships among charge, force, and distance. The charge of two particles and the location of those particles may be adjusted and the Coulomb force between them observed. The force is displayed both vectorially and numerically as the distance between the objects changes. Web <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px;"> Electric Field Dipole Simulate the electric field created by two point charges from arbitrary test points, to produce a graphical display of the electric field lines through these points. Web Force Equation The main difference between the formulas for electrical force and gravitational force is that gravitational forces are always attractive, whereas electrical forces can be attractive or repulsive. There are two kinds of electrical charges: positive and negative.Video (2 minutes) <span style="font-family: Arial,Helvetica,sans-serif;"> <span style="background-color: #c5eafc; color: #006497; display: block; font-size: 12px; text-decoration: none;">Fundamental Forces (Series: The Mechanical Universe) A variety of phenomena in the universe can be described by four forces. Two nuclear forces (strong and weak) exist within the atomic nucleus. The fundamental force of gravity ranges across the universe. Electricity, the fourth fundamental force, binds the atoms of all matter. Video (29 minutes) Inverse Square Law <span style="font-family: Arial,Helvetica,sans-serif; font-size: 11px;">Explore the inverse square law as it applies to gravitational and electric fields. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px;"> Web/Video

Faraday Cage The effects of an electric field on a conductor are described. The electric field inside a conductor becomes zero. A Faraday cage is demonstrated as it prevents an electric field from entering and affecting a gold leaf electroscope. The steel structure of a bridge also acts as a Faraday cage, preventing electromagnetic radio waves from entering.Video (4 minutes) <span style="font-family: Arial,Helvetica,sans-serif;"> Gauss' Law The mathematical contributions of Carl Gauss were an elegant compliment to Michael Faraday's common sense ideas about an electric field. Gauss' law is described as having the total electric flux being directly related to the amount of electric charge producing the flux. With no net charge, the total flux exiting a closed surface will always equal the total flux entering the same surface. Gauss confirmed the mathematical expression of the inverse square law.Video (2 minutes)

Capacitance and Potential (Series: The Mechanical Universe...and Beyond) This video provides historical information about Benjamin Franklin's contributions to the theory of electricity. Franklin was the first to propose a successful theory of the Leyden Jar. He also gave positive and negative charges their names and invented the parallel plate capacitor. The video also discusses electrical potential, the potential of charged conductors, equipotential, and capacitance.Video (29 minutes) Electric Field Potential, Non-Uniform Explore the electric potential in a non-uniform electric field produced by a point charge by analyzing the potential and kinetic energy of a charged particle moving within the field. Web Electric Field Potential, Uniform Explore the electric potential in a uniform electric field by analyzing the potential and kinetic energy of a charged particle moving within the field.Web Electric Properties - Potential The nature of electric potential is described. This video includes an illustration of the three-dimensional shape of the electric field.Video (6 minutes) Electrical Force vs. Gravitational Force Benjamin Franklin uses Sir Isaac Newton's ideas about gravitational force to further develop his theories about electric forceVideo (1 minute) <span style="background-color: #c5eafc; color: #006497; display: block; font-size: 12px; text-decoration: none;"> Voltage, Energy and Force (Series: The Mechanical Universe...and Beyond) This video explores the electric potential and its gradient; the potentials of atoms and metals; electric energy; and the reason why sparks jump.Video (29 minutes) <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13px; line-height: 19px;"> Electric Potential: The Atom vs. Van de Graaff The difference in electric potential between the Van de Graaff generator and an atom is illustrated.Video (3 minutes) How a Spark is Created The transfer of charge in air and the chain reaction causing a spark are illustrated in this video.Video (3 minutes)

<span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; text-align: left;"><span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: 13px; line-height: 19px;"> Potential Difference of a Battery This video illustrates how a battery can be used to produce an electric field and potential difference in two pieces of metal. Also, a derivation of q = CV is provided.Video (1 minute) The Electric Field This video presents an illustration of electric fields around metal objects and explains the potential difference between two charged objectsVideo (2 minutes) Work, Electric Force, and Potential Difference The use of test charges, work, potential energy, and the electric force are illustrated. Also, electric potential (voltage) is illustrated and derived. Video (2 minutes) Electric Field Source An electric field always originates at the source of charge. The size of any charged, spherically-shaped object has no impact on the strength of the electric field; it is only the total amount of charge present that matters.Video (1 minute) Inverse Square Law Explore the inverse square law as it applies to gravitational and electric fields.Web/Video

Lightning and Capacitors Benjamin Franklin's ideas about lightning are developed from a historical perspective, including his original experiments with lightning. Also, Franklin's discovery of the capacitor and the movement of charge on a Leyden jar are explained using animation.Video (5 minutes) Work, Electric Force, and Potential Difference The use of test charges, work, potential energy, and the electric force are illustrated. Also, electric potential (voltage) is illustrated and derived.Video (2 minutes) Particle in an Electric Field Simulate the motion of a charged particle traveling in a uniform electric field in order to explore how the particle's acceleration is affected by the electric field magnitude, direction, as well as the particle's charge and mass.Web Millikan Experiment Simulate the Millikan Oil Drop Experiment and determine the elementary charge. Web/Video

The Millikan Experiment Robert Andrews Millikan adapted J.J. Thomson and H.A. Wilson's cloud chamber. The water normally used in a cloud chamber was replaced with oil and the size of an individual oil droplet was determined by measuring its terminal velocity. By knowing the size of the droplet and by adjusting the electric field to produce a constant upward velocity on the oil droplet, Millikan determined the precise value of the charge of an electron. Animation is included to explain this concept.Video (10 minutes) The Millikan Experiment (Series: The Mechanical Universe) Science progresses by painstaking trial and error. This is illustrated by Robert Andrews Millikan's classic oil-drop experiment. Knowing the electric force acting on a charged droplet and the viscosity of the droplet, Millikan was able to determine the charge of a single electron.Video (29 minutes)

Scientific Judgment Dr. Goodstein demonstrates Robert Andrews Millikan's original experimental equipment. Millikan's private lab notebook reveals an apparent bias in his data collection. The apparent bias is actually a demonstration of Millikan's scientific judgment. He examined the apparatus each time an unexpected value was obtained and eliminated these values based on a source of error.Video (6 minutes) The History of Electric Lights This video presents a historical overview of the early developments surrounding the neon light.Video (2 minutes) Contribution to the Scientific Method Robert Andrews Millikan was both precise and creative. He strove to eliminate error through tremendous diligence. Millikan extolled the scientific method, believing that nature should dictate the answers to research questions; determining the significance of the data should be the job of the scientist's peers. He was awarded the Nobel Prize in 1923 and at the time, he was considered one of America's foremost scientists.Video (2 minutes)  || <span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Ampere's Law and Equations <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; line-height: 16px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video shows a mathematical derivation of the constant equations for magnetic fields. Ampere's law is included. Video (3 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Earth's Magnetic Field <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">The Earth, the stars, and our sun are defined as being magnets. Some observable effects of planetary magnetic fields are explored. Video (2 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Earth's Magnetic Field and Navigation <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video shows how a compass is used for navigation; the Earth's magnetic field is also discussed. <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Video (1 minute)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Gravity, Electricity and Magnetism (Series: The Mechanical Universe) <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">The gravitational force between two masses, the electrical force between two charges, and the magnetic force between two magnetic poles essentially take the same mathematical form. Sir Isaac Newton's script suggested connections between electricity and magnetism. Acting on scientific hunches, James Clerk Maxwell saw the matter in an entirely new light. Video (29 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Intro to E and M <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This ExploreLearning Gizmo allows the user to become familiar with the principles of electricity and magnetism. The simulation provides an overview of electrical current, charged particles, resistance, voltage, and magnetism. Step-by-step activities using balloons, a circuit builder, and magnets are featured in support material to demonstrate key concepts. Web

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Lorentz Force <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Animation is used to describe the Lorentz equation and show how this equation creates circular motion. This video also describes how the Earth's magnetic field protects the atmosphere from charged particles in the solar wind. The origin of the aurora is discussed. Video (2 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Magnetic Field Through a Loop <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Explore the magnitude and direction of the magnetic field produced by a current-carrying conductive loop. This applet may be used by itself or in conjunction with the accompanying lesson. Web

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Magnetic Fields Produced by Electric Current <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video describes André-Marie Ampère's life during the French Revolution. It includes an illustrative animation (with equations) describing the magnetic field produced by a moving current in a straight conductor, a solenoid, and a toroid. Video (4 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Magnetic Flux <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">In this video, magnetic flux is defined. A comparison is made between the electric flux and magnetic flux, and the equations of magnetic flux are described including Gauss' law. Video (3 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Magnetic, Electric and Gravitational Force Similarities <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Certain similarities exist between electric, magnetic, and gravitational forces. While magnetic fields exit one pole and enter another, electric and gravitational fields originate from a point source. Other than this, they all obey similar force laws. Video (2 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Magnetism (Series: The Mechanical Universe...and Beyond) <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video explores the natural phenomenon of magnetism, the behaviour of magnetic materials, and the motion of charged particles in a magnetic field. Video (29 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Maxwell's Theory <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">James Clerk Maxwell understood the significance of the constants of light, electricity, and magnetism. He went on to discover that the electric and magnetic constants are related to one another by the speed of light. This inspired him to develop a combined theory that unified the concepts of electricity, magnetism, and light. A demonstration helps illustrate this concept. Video (5 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">The Compass <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">In this video, the explanation for the magnetic functions of a compass and the size of the Earth's magnetic field are described. Video (2 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">The Earth and Sun: Magnetic Fields <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">In this video the source, impacts, and movement of magnetic fields are described. Video (3 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">The Magnetic Field (Series: The Mechanical Universe...and Beyond) <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video explores the relationship between magnetic fields and electric currents. It introduces the work of André-Marie Ampère and the Biot-Savart law concerning the effects of an electric current on a magnetic field. Video (29 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">The Nature of Magnetism <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">In this video, electric, gravitational, and magnetic forces are compared. Magnetic equations of repulsion and attraction are described. Video (1 minute)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">The Polar Nature of Magnetism <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video discusses the possible existence of a magnetic monopole. The Earth is described as a magnetic dipole. The concept of a dipole is illustrated and compared to an electric dipole. Video (2 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Creating Current with a Magnetic Field <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Animation is used to show that a wire moving perpendicular to a magnetic field will cause a current to move in the wire. Moving a bar magnet up and down through the centre of a wire loop will cause a current to flow in the wire. This video also describes Faraday's law of electromagnetic induction. Video (3 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Faraday and Maxwell <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">The scientific relationship between Michael Faraday and James Clerk Maxwell is explored in this video. Together, they formed a clear idea of an electric field. Video (2 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Faraday's Contribution to Science <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video describes the value of Michael Faraday's ideas on electromagnetic induction. Video (3 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Faraday's Discovery of Electromagnetic Induction <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video presents a historical perspective on the discovery of electromagnetic induction. The discussion includes the Dutch windmill, the steam engine, and the first electric motor. Michael Faraday's discovery of how to produce an electric current using a magnetic field is also described. Video (5 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Faraday's Electric Field <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Michael Faraday's analysis of the inverse square relationship and his ideas about the lines of force and their directions led to our modern electric field theory. For Faraday, the inverse square law meant that the field must propagate from a single point in space. The direction of the lines of force goes from a positive to a negative charge. The intensity of the lines is large when close to the source, and small when far away from the source. Therefore, the amount of force is related to the intensity of the field lines. Video (2 minutes) <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"> <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Field Theory <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">This video discusses the development of field theory. Charles Coulomb was the first to demonstrate the inverse square law (Coulomb's law) and by doing so described the relationship between distance and force for all fields. The rationalization of “action at a distance” is discussed. Video (4 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Oersted's Discovery <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video demonstrates Hans Christian Oersted's discovery that electric current produces a magnetic field perpendicular to the direction of the electric current. Video (<1 minute)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Oersted's Discovery <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Hans Christian Oersted's discovery of the connection between electricity and magnetism is re-enacted with a demonstration by Dr. Goodstein. Oersted found that passing electric current through a wire could deflect a compass needle. Dr. Goodstein explains the circumstances and impact of Oersted's discovery. Video (6 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Summary - Modern Field Theory <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Michael Faraday's lines of force were replaced by the modern field theory of James Clerk Maxwell. Knowing the evolution of Faraday's ideas and how these led to current theory can tell us something about the nature of scientific discovery. Video (3 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">The First Electric Motor <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Michael Faraday considered how to harness the electromagnetic force and set out, in 1821, to create a device to do it. This device was the first electric motor, and it used real forces in real space. Video (1 minute)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Magnetic Field Surrounding a Wire <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Explore the magnitude and direction of the magnetic field surrounding a conventional or electron current-carrying conductor. Web/Video

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Magnetic Fields Produced by Electric Current <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video describes André-Marie Ampère's life during the French Revolution. It includes an illustrative animation (with equations) describing the magnetic field produced by a moving current in a straight conductor, a solenoid, and a toroid. Video (4 minutes)

<span style="background-color: #c5eafc; color: #006497; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">The Interaction Between Current-Carrying Wires <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">This video demonstrates how two current-carrying wires will repel or attract based on the direction of the magnetic fields. It also explores André-Marie Ampère's theory of electrodynamics as it applies to straight wires, solenoids, and toroids. Video (3 minutes) <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"> <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Particle in a Magnetic Field <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">Simulate the motion of a charged particle in a uniform magnetic field and explore the relationship between the field strength and the particle's charge and velocity. Web <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"> <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Electromagnetic Induction - Demonstrations <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">This video shows three demonstrations of electromagnetic induction: how a solenoid and toroid can induce current in an external wire; how the mechanical energy of a pendulum can be converted into heat by an external magnetic field; and how a magnetic field can create mechanical energy in a metal object. Video (6 minutes) <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"> <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Electromagnetic Induction (Series: The Mechanical Universe...and Beyond) <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">After Oersted's discovery that electric currents create magnetism, it was obvious that magnetism should be able to create electric currents. The 1831 discovery of electromagnetic induction by Faraday and Henry was one of the most important of the 19th century. Electromagnetic induction is now the means by which nearly all electric power is generated. Video (29 minutes) <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"> <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Generating Current <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">This video discusses how and why Thomas Edison and Nikola Tesla created the first commercial generators. Animations show current generated by moving loops of wire in an external magnetic field. Also included is an overview of hydro, wind, geothermal, and solar energy options. Electromagnetic induction is described as the basis for all electrical generation. Video (5 minutes) <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"> <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Self-induction and Lenz's Law <span style="background-color: #fdfef5; display: block; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;"><span style="font-family: Arial,Helvetica,sans-serif;">Animation shows how an induced current creates a magnetic flux which opposes the external magnetic flux. Self-induction is defined. Faraday's law, inductance, and solenoid self-induction are described. Video (2 minutes) <span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Alternating Currents (AC) Advantages <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">For reasons of efficiency, electricity must be transmitted at high voltage to reduce power loss due to heat. Since AC (alternating current) voltage can be raised and lowered relatively easily using a transformer, efficient power distribution over very long transmission wires is possible. Video (4 minutes) <span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Alternating Currents (AC) Animation <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">Alternating current (AC) is an oscillating current produced by a voltage that rises and falls like a sine wave. Video (<1 minute) <span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Alternating Currents (AC) Circuit <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">Differential equations show how resonance and a small oscillating voltage will create a very large current. Video (2 minutes)

<span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Alternating Currents (Series: The Mechanical Universe...and Beyond) <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">Electromagnetic induction makes it easy and natural to generate alternating current. The use of transformers makes it practical to distribute alternating current over long distances. Video (29 minutes) <span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left; text-decoration: none;">Alternating Currents: Introduction <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">This video provides an overview of how alternating current (AC) electric power is generated. Dr. Goodstein also demonstrates a water-driven AC generator. Video (2 minutes) <span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Direct Currents (DC) Animation <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">Direct current (DC) is a steady flow of current produced by a constant voltage. Video (<1 minute) <span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Faraday's Discovery of Electromagnetic Induction <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">This video presents a historical perspective on the discovery of electromagnetic induction. The discussion includes the Dutch windmill, the steam engine, and the first electric motor. Michael Faraday's discovery of how to produce an electric current using a magnetic field is also described. Video (5 minutes) <span style="background-color: #c5eafc; color: #006497; font-family: Verdana,Arial,Helvetica,sans-serif; font-size: 12px; text-align: left;">Resonating Circuits <span style="background-color: #fdfef5; display: block; font-family: Arial,Helvetica,sans-serif; font-size: 11px; text-align: left;">Tuned resonating circuits in radios and televisions are described mathematically. Electrical resonance will occur with an inductor and oscillating current. An inductor will oppose changing currents just as a spring opposes mechanical movements; therefore, an inductor can oscillate in resonance. A resistor is used to control the resonance. Video (4 minutes)

||