Electromagnetic Field Theory

2nd Year EE Students

Prof. Dr. Magdi El-Saadawiwww.saadawi1.net

saadawi1@gmail.com

2014/2015

Chapter 5

Stationary Magnetic Fields

(Magnetostatics)

Chapter 5

Stationary Magnetic Fields5.1. Introduction 5.2. Force on a Moving Charge5.3. Force on a Current-Carrying Conductor in an External

Magnetic Field5.4 Generation of a Magnetic Field 5.5. Boundary Conditions for the Magnetic Induction5.6. Vector Potential of the Magnetic Field5.7. The Magnetic Field Intensity (Magnetic Excitation)5.8. Field Equation and Boundary Conditions for Magnetic Field

Intensity

5.9. Applications of Ampere’s Law 5.10. The Nature of Magnetic Materials

5.10. The Nature of Magnetic Materials 5.11. General Solution of Stationary Magnetic Fields5.12. Biot-Savart Law5.13. The Scalar Magnetic Potential5.14 Magnetic Torque and Moment5.15. Magnetic Dipole5.16. Magnetization in Materials5.17. Inductors and Inductances5.18. Magnetic Energy5.19 Magnetic Circuits

Chapter 5

Stationary Magnetic Fields

A small current loop or a short permanent magnet

can be considered as a magnetic dipole.

5.16 Magnetization in Materials

To understand Magnetization in the Materials,

let’s first discuss what happen in the entire of the

material.

An internal magnetic field is produced by

electrons orbiting around the nucleus as in Fig.

5.17 a

5.16 Magnetization in Materials

Both of these electronic motions produce internal

magnetic fields B, that are similar to the magnetic

field produced by a current loop (Fig. c.) with a

magnetic moment of

Without an external B field applied to the material,

the sum of m's is zero due to random orientation

as in Fig. 5.18 (a).

When an external B field is applied, the magnetic

moments of the electrons more or less align

themselves with B so that the net magnetic

moment is not zero as in Fig. 5.18 (b).

5.16 Magnetization in Materials

5.16 Magnetization in Materials

5.16 Magnetization in Materials

5.16 Magnetization in Materials

5.16 Magnetization in Materials

5.16 Magnetization in Materials

5.16 Magnetization in Materials

Magnetic materials can be roughly classified into

three main groups in accordance with their μr :

Diamagnetic, Paramagnetic, Ferromagnetic.

5.10. The Nature of Magnetic Materials

5.10. The Nature of Magnetic Materials

5.10. The Nature of Magnetic Materials

5.10. The Nature of Magnetic Materials

5.17 Inductors and Inductances

5.17 Inductors and Inductances

5.17 Inductors and Inductances

5.17 Inductors and Inductances

5.17 Inductors and Inductances

5.17 Inductors and Inductances

5.17 Inductors and Inductances

5.17 Inductors and Inductances

5.18. Magnetic Energy

1. Determine the self-inductance of a coaxial cable

of inner radius a and outer radius b

Problems

Problems

Problems

Problems