The course notes were written by John Belcher, Peter Dourmashkin, and Sen-Ben Liao.
Magnetism (磁 (じ) 力 (りょく), Jiryoku?) was the Quirk used by Kenji Hikiishi. 1 Description 1.1 Weaknesses 2 Usage 3 Named Super Moves 4 References 5 Site Navigation Magnetism allows Kenji to magnetize people around her, up to a 4.5-meter radius of herself at will. She can magnetize a person's entire body or specific portions. Once magnetized, the targets either attract or repel each. Magnetism definition is - a class of physical phenomena that include the attraction for iron observed in lodestone and a magnet, are inseparably associated with moving electricity, are exhibited by both magnets and electric currents, and are characterized by fields of force. How to use magnetism.
- MAGNETISM Magnetism brings to mind horseshoe magnets and iron filings. However, magnetism is very closely related to electricity. In 1819 the Danish physicist and chemist, Hans Christian Oersted (1777-1851), during a lecture demonstration, observed that an electric current can affect a magnetic compass needle. and thus united what until then had been viewed as two distinct subjects1.
- This video provides an introduction to basic concepts in magnetism, including magnetic poles, magnetic fields, and electromagnets. It is a useful reference f.
- Magnetism, phenomenon associated with magnetic fields, which arise from the motion of electric charges. It can be an electric current in a conductor or charged particles moving through space, or it can be the motion of an electron in an atomic orbital. Learn more about magnetism in this article.
The TEAL classroom includes the opportunity for students to use the Personal Response System (PRS). Questions are posed to the class to stimulate discussion and indicate how concepts are going over. Students 'vote' on answers electronically and their answers are tallied.
WEEK # | SES # | TOPICS | COURSE NOTES | PRESENTATIONS | PRS |
---|---|---|---|---|---|
1 | 1 | Hour 1 Why Physics? Why Studio Physics? (and How?) Vector and Scalar Fields Hour 2 Gravitational Fields Electric Fields | Chapter 1: Sections 1.1 - 1.6; 1.8 (PDF) Chapter 2 (PDF) | (PDF) | (PDF) |
2 | Hour 1 Review: Electric Fields Charge Dipoles Hour 2 Continuous Charge Distributions | Chapter 1: Section 1.6 (PDF) Chapter 2 (PDF) | (PDF) | (PDF) | |
3 | Problem Solving Session 1: Line and Surface Integrals | ||||
2 | 4 | Hour 1 Working In Groups Experiment 1: Visualizations Hour 2 Electric Potential | Chapter 3: Sections 3.1 - 3.5 (PDF) | (PDF) | (PDF) |
5 | Hour 1 Gauss' Law Windows virtual desktop remote desktop app. Hour 2 Gauss' Law | Chapter 4 (PDF) | (PDF) | (PDF) | |
6 | Problem Solving Session 2: Electric Field of Continuous Charge Distributions | ||||
3 | 7 | Hour 1 Conductors and Insulators Experiment 2: Electrostatic Force Hour 2 | Chapter 4: Sections 4.3 - 4.4 (PDF) Chapter 5 (PDF - 1.3 MB) | (PDF) | (PDF) |
8 | Hour 1 Last Time: Conductors Experiment 3: Faraday Ice Pail Hour 2 Capacitors and Dielectrics | Chapter 4: Sections 4.3 - 4.4 (PDF) Chapter 5 (PDF - 1.3 MB) | (PDF) | (PDF) | |
9 | Problem Solving Session 3: Gauss' Law | Chapter 4 (PDF) | |||
4 | 10 | Hour 1 DC Circuits Hour 2 Kirchhoff's Loop Rules | Chapter 6 (PDF) Chapter 7: Sections 7.1 through 7.4 (PDF) | (PDF - 1.2 MB) | (PDF) |
11 | Problem Solving Session 4: Capacitance | Chapter 5 (PDF - 1.3 MB) | |||
5 | 12 | Hour 1 Working with Circuits Experiment 4: Part I: Measuring V, I, R Hour 2 RC Circuits Experiment 4: Part II: RC Circuits | Chapter 7 (PDF) | (PDF) | (PDF) |
13 | Hour 1 Concept Review/Overview PRS Questions - Possible Exam Questions Hour 2 Sample Exam | (PDF) | (PDF) | ||
6 | 14 | Hour 1 Magnetic Fields Experiment 5: Magnetic Fields Hour 2 Charges moving in B Fields Exam Review | Chapter 8 (PDF) | (PDF) | (PDF) |
15 | Hour 1 Magnetic Force Experiment 6: Magnetic Force Hour 2 Creating B Fields: Biot-Savart | Chapter 9: Sections 9.1 - 9.2 (PDF - 1.9 MB) | (PDF - 1.1 MB) | (PDF) | |
16 | Problem Solving Session 5: Magnetic Torque and Moments | Chapter 8: Sections 8.3 - 8.4 (PDF) Chapter 9: Sections 9.1 - 9.2 (PDF - 1.9 MB) | |||
7 | 17 | Hour 1 Dipoles and Magnetic Fields Hour 2 Experiment 7: Dipoles in B Fields | Chapter 8: Section 8.4 (PDF) Chapter 9: Sections 9.1 - 9.2, 9.5 (PDF - 1.9 MB) | (PDF) | (PDF) |
18 | Hour 1 Levitation Experiment 8: Magnetic Forces Hour 2 Ampere's Law | Chapter 9 (PDF - 1.9 MB) | (PDF - 1.6 MB) | (PDF) | |
19 | Problem Solving Session 6: Ampere's Law | Chapter 9: Sections 9.3 - 9.4; 9.10.2, 9.11.6, 9.11.7 (PDF - 1.9 MB) | |||
8 | 20 | Hour 1 Faraday's Law Hour 2 Faraday's Law: Applications | Chapter 10 (PDF) | (PDF) | (PDF) |
21 | Hour 1 Experiment 9: Faraday's Law Hour 2 Faraday's Law Transformers Magnetic Materials | Chapter 10 (PDF) Chapter 11: Section 11.1 (PDF - 1.0 MB) | (PDF) | (PDF) | |
22 | Problem Solving Session 7: Faraday's Law | Chapter 10 (PDF) | |||
9 | 23 | Hour 1 Concept Review/Overview PRS Questions - Possible Exam Questions Hour 2 Sample Exam | (PDF) | (PDF) | |
24 | Hour 1 Inductance and LR Circuits Hour 2 Energy in Inductors | Chapter 11: Sections 11.1 - 11.4 (PDF - 1.0 MB) | (PDF) | (PDF - 1.3 MB) | |
10 | 25 | Hour 1 Experiment 10: Part I: Measuring L LC Circuits Hour 2 Experiment 10: Part II: LRC Circuit | Chapter 11: Sections 11.5 - 11.6 (PDF - 1.0 MB) | (PDF) | (PDF) |
26 | Hour 1 Driven Harmonic Motion (RLC) Hour 2 Experiment 11: Driven RLC Circuit | Chapter 12 (PDF) | (PDF) | (PDF) | |
27 | Problem Solving Session 8: Driven RLC Circuits | Chapter 12 (PDF) | |||
11 | 28 | Hour 1 Displacement Current Maxwell's Equations Hour 2 Electromagnetic Waves | Chapter 13 (PDF) | (PDF) | (PDF) |
29 | Problem Solving Session 9: Displacement Current, Poynting | Chapter 13 (PDF) | |||
12 | 30 | Hour 1 Traveling and Standing Waves Hour 2 Electromagnetic (EM) Waves | Chapter 13 (PDF) | (PDF) | (PDF) |
31 | Hour 1 Concept Review/Overview PRS Questions - Possible Exam Questions Hour 2 Sample Exam | (PDF) | |||
13 | 32 | Hour 1 Generating Electromagnetic Waves Plane EM Waves Electric Dipole EM Waves Hour 2 Experiment 12: Microwaves Review Exam 3 Results | Chapter 13 (PDF) | (PDF - 2.9 MB) | (PDF) |
33 | Hour 1 Interference Hour 2 Experiment 13: Interference | Chapter 14 (PDF) | (PDF - 1.4 MB) | (PDF) | |
34 | Problem Solving Session 10: Interference | ||||
14 | 35 | Hour 1 The Structure of Space and Time Hour 2 The Structure of Space and Time | |||
36 | Hour 1 Concept Review/Overview PRS Questions - Possible Exam Questions Hour 2 Sample Exam | (PDF) |
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Article - Magnetic forces
- Magnetic properties of matter
- Ferromagnetism
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Join Britannica's Publishing Partner Program and our community of experts to gain a global audience for your work! Frank Neville H. RobinsonSee All ContributorsSenior Research Officer, Clarendon Laboratory, University of Oxford; Fellow, St. Catherine's College, Oxford, 1962–92. Author of Noise and Fluctuations in Electronic Devices and Circuits and others.
Magnetism, phenomenon associated with magnetic fields, which arise from the motion of electric charges. This motion can take many forms. It can be an electric current in a conductor or charged particles moving through space, or it can be the motion of an electron in an atomicorbital. Magnetism is also associated with elementary particles, such as the electron, that have a property called spin.
Fundamentals
Magnetism Definition For Kids
Basic to magnetism are magnetic fields and their effects on matter, as, for instance, the deflection of moving charges and torques on other magnetic objects. Evidence for the presence of a magnetic field is the magnetic force on charges moving in that field; the force is at right angles to both the field and the velocity of the charge. This force deflects the particles without changing their speed. The deflection can be observed in the torque on a compass needle that acts to align the needle with the magnetic field of Earth. The needle is a thin piece of iron that has been magnetized—i.e., a small bar magnet. One end of the magnet is called a north pole and the other end a south pole. The force between a north and a south pole is attractive, whereas the force between like poles is repulsive. The magnetic field is sometimes referred to as magnetic induction or magnetic flux density; it is always symbolized by B. Magnetic fields are measured in units of tesla (T). (Another unit of measure commonly used for B is the gauss, though it is no longer considered a standard unit. One gauss equals 10−4 tesla.)
A fundamental property of a magnetic field is that its flux through any closed surface vanishes. (A closed surface is one that completely surrounds a volume.) This is expressed mathematically by div B = 0 and can be understood physically in terms of the field lines representing B. These lines always close on themselves, so that if they enter a certain volume at some point, they must also leave that volume. In this respect, a magnetic field is quite different from an electric field. Electric field lines can begin and end on a charge, but no equivalent magnetic charge has been found in spite of many searches for so-called magnetic monopoles.
The most common source of magnetic fields is the electric current loop. It may be an electric current in a circular conductor or the motion of an orbiting electron in an atom. Associated with both these types of current loops is a magnetic dipole moment, the value of which is iA, the product of the current i and the area of the loop A. In addition, electrons, protons, and neutrons in atoms have a magnetic dipole moment associated with their intrinsic spin; such magnetic dipole moments represent another important source of magnetic fields. A particle with a magnetic dipole moment is often referred to as a magnetic dipole. (A magnetic dipole may be thought of as a tiny bar magnet. It has the same magnetic field as such a magnet and behaves the same way in external magnetic fields.) When placed in an external magnetic field, a magnetic dipole can be subjected to a torque that tends to align it with the field; if the external field is not uniform, the dipole also can be subjected to a force.
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All matter exhibits magnetic properties to some degree. When placed in an inhomogeneous field, matter is either attracted or repelled in the direction of the gradient of the field. This property is described by the magnetic susceptibility of the matter and depends on the degree of magnetization of the matter in the field. Magnetization depends on the size of the dipole moments of the atoms in a substance and the degree to which the dipole moments are aligned with respect to each other. Certain materials, such as iron, exhibit very strong magnetic properties because of the alignment of the magnetic moments of their atoms within certain small regions called domains. Under normal conditions, the various domains have fields that cancel, but they can be aligned with each other to produce extremely large magnetic fields. Various alloys, like NdFeB (an alloy of neodymium, iron, and boron), keep their domains aligned and are used to make permanent magnets. The strong magnetic field produced by a typical three-millimetre-thick magnet of this material is comparable to an electromagnet made of a copper loop carrying a current of several thousand amperes. In comparison, the current in a typical light bulb is 0.5 ampere. Since aligning the domains of a material produces a magnet, disorganizing the orderly alignment destroys the magnetic properties of the material. Thermal agitation that results from heating a magnet to a high temperature destroys its magnetic properties.
Magnetic fields vary widely in strength. Some representative values are given in the Table.
Magnetism Definition
Typical magnetic fields | |
---|---|
inside atomic nuclei | 1011 T |
in superconducting solenoids | 20 T |
in a superconducting coil cyclotron | 5 T |
near a small ceramic magnet | 0.1 T |
Earth's field at the Equator | 4(10−5) T |
in interstellar space | 2(10−10) T |
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