Learning Objectives By the end of this section, you will be able to: Eddy Currents and Magnetic Damping As discussed in Motional Emf, motional emf is induced when a conductor moves in a magnetic field or when a magnetic field moves…
Learning Objectives By the end of this section, you will be able to: As we have seen, any change in magnetic flux induces an emf opposing that change—a process known as induction. Motion is one of the major causes of…
Learning Objectives By the end of this section, you will be able to: Faraday’s and Lenz’s Law Faraday’s experiments showed that the emf induced by a change in magnetic flux depends on only a few factors. First, emf is directly…
Learning Objectives By the end of this section, you will be able to: The apparatus used by Faraday to demonstrate that magnetic fields can create currents is illustrated in Figure 23.3. When the switch is closed, a magnetic field is produced…
Figure 23.1 These wind turbines in the Thames Estuary in the UK are an example of induction at work. Wind pushes the blades of the turbine, spinning a shaft attached to magnets. The magnets spin around a conductive coil, inducing an electric…
Magnets Ferromagnets and Electromagnets Magnetic Fields and Magnetic Field Lines Magnetic fields can be pictorially represented by magnetic field lines, the properties of which are as follows: Magnetic Field Strength: Force on a Moving Charge in a Magnetic Field Force…
Learning Objectives By the end of this section, you will be able to: Mass Spectrometry The curved paths followed by charged particles in magnetic fields can be put to use. A charged particle moving perpendicular to a magnetic field travels…
Learning Objectives By the end of this section, you will be able to: You might expect that there are significant forces between current-carrying wires, since ordinary currents produce significant magnetic fields and these fields exert significant forces on ordinary currents.…
Learning Objectives By the end of this section, you will be able to: How much current is needed to produce a significant magnetic field, perhaps as strong as the Earth’s field? Surveyors will tell you that overhead electric power lines…
Learning Objectives By the end of this section, you will be able to: Motors are the most common application of magnetic force on current-carrying wires. Motors have loops of wire in a magnetic field. When current is passed through the loops,…