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📚 College Physics 2e
Chapters ▾
1 Introduction: The Nature of Science and Physics2 Kinematics3 Two-Dimensional Kinematics4 Dynamics: Force and Newton's Laws of Motion5 Further Applications of Newton's Laws: Friction, Drag, and Elasticity6 Uniform Circular Motion and Gravitation7 Work, Energy, and Energy Resources8 Linear Momentum and Collisions9 Statics and Torque10 Rotational Motion and Angular Momentum11 Fluid Statics12 Fluid Dynamics and Its Biological and Medical Applications13 Temperature, Kinetic Theory, and the Gas Laws14 Heat and Heat Transfer Methods15 Thermodynamics16 Oscillatory Motion and Waves17 Physics of Hearing18 Electric Charge and Electric Field19 Electric Potential and Electric Field20 Electric Current, Resistance, and Ohm's Law21 Circuits and DC Instruments22 Magnetism23 Electromagnetic Induction, AC Circuits, and Electrical Technologies24 Electromagnetic Waves25 Geometric Optics26 Vision and Optical Instruments27 Wave Optics28 Special Relativity29 Quantum Physics30 Atomic Physics31 Radioactivity and Nuclear Physics32 Medical Applications of Nuclear Physics33 Particle Physics34 Frontiers of Physics

Chapter 23: Electromagnetic Induction, AC Circuits, and Electrical Technologies

Wind turbine with three blades moored in shallow water.
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 current in the coil, and eventually feeding the electrical grid.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 current in the coil, and eventually feeding the electrical grid. (credit: modification of work by Petr Kratochvil)

Nature’s displays of symmetry are beautiful and alluring. A butterfly’s wings exhibit an appealing symmetry in a complex system. (See Figure 23.2.) The laws of physics display symmetries at the most basic level—these symmetries are a source of wonder and imply deeper meaning. Since we place a high value on symmetry, we look for it when we explore nature. The remarkable thing is that we find it.

Photograph of a butterfly with its wings spread out symmetrically is shown to rest on a bunch of flowers.
Figure 23.2 Physics, like this butterfly, has inherent symmetries.Physics, like this butterfly, has inherent symmetries. (credit: Thomas Bresson)

Adapted from College Physics 2e by OpenStax (openstax.org), licensed under CC BY-NC-SA 4.0. Changes were made. License: CC-BY-NC-SA-4.0.