OVERVIEW

The undergraduate course “Electromagnetic Fields” introduces and develops basic ideas related to the electromagnetic fundamental laws, to the interaction of electromagnetic fields with matter, to electromagnetic waves. Its aim is to provide the students with the essential tools for understanding the electromagnetic phenomena and the many practical applications of electromagnetic fields.

AIMS AND CONTENT

LEARNING OUTCOMES

Essential tools for understanding electromagnetic phenomena and the countless practical applications of electromagnetic fields.

AIMS AND LEARNING OUTCOMES

The course provides the students the basic notions related to electromagnetic fields. During the lectures the electromagnetic fundamental laws, the interaction of electromagnetic fields with matter, the extensions of the laws of conservation of energy and momenta to electromagnetics, and the simplest electromagnetic waves are presented. The course aim is to provide the essential tools for understanding the electromagnetic phenomena and the many practical applications of
electromagnetic fields.
Al the end of the course, the student will be able to describe the main concepts of electrodynamics in the presence of charges in vacuum and in the presence of ponderable media. They will also be able to solve simple electromagnetic problems related to important practical applications.

PREREQUISITES

Exams of General Physics and Mathematical Analysis; basic notions of Mathematical Methods for Engineering

TEACHING METHODS

All teaching activities are presented in the classroom by the teacher.

SYLLABUS/CONTENT

1. Course organization, motivation and applications (1.5; 1.5)
2. Some comments on Newtonian, relativistic and quantum physics; the role of classical relativistic electrodynamics in modern physics; some links between classical relativistic and quantum electrodynamics in simple cases; some properties of photons; number and properties of photons involved in many engineering applications (3; 4.5)
3. Recalling some prerequisites: electric charge; different models for electric charge distributions; electric current; different models for the electric current density; the law of conservation of charge; Lorentz force; Maxwell's equations in the presence of charges in vacuum in integral form; differential operators, the fundamental theorems of vector calculus (3.5; 8)
4. Electromagnetic fields in the presence of ponderable media:
4.1 considerations on the definition of macroscopic fields and the fundamental laws for the macroscopic electromagnetic field in the presence of charges in vacuum (1; 9)
4.2 some considerations on the constituents of matter (0.5; 9.5)
4.3 drawbacks of the approach based on the microscopic Maxwell's equations (0.5; 10)
4.4 analysis of the interaction of the macroscopic electromagnetic field with matter (0.5; 10.5)
4.5 hints at electrical conduction (recalls of things seen in other courses): chaotic Brownian-type motions of mobile carriers, motions due to diffusion phenomena of mobile carriers, motions due to external forces, currents in the presence of different types of carriers (1; 11.5)
4. 6 electric polarization: effects of an electrostatic field on atoms and molecules, electrostatic potential generated by particular configurations or distributions of electric charges, electric dipole and electric dipole moment, electric dipole moment density per unit volume, volumetric and surface densities of electric charges equivalent to electric dipole moment density per unit volume, electric charges equivalent to polarization, electric displacement and generalization of Gauss's law, time variant case, first generalization of Ampere-Maxwell's law in global form (6; 17. 5)
4.7 magnetic polarization: effects of a magnetostatic field on matter, the magnetic induction field created by a direct current in a circular loop, magnetic dipole moment, magnetic dipole moment density per unit volume, electric current density per unit area and per unit length equivalent to magnetic dipole moment density per unit volume, electric currents equivalent to magnetic polarization, magnetic field and the second and final generalization of Ampere-Maxwell's law (3; 20.5)
4.8 Fundamental electromagnetic field equations (in the presence of matter) in global form (0.5; 21)
4.9 Fundamental electromagnetic field equations (in the presence of matter) in local form (1; 22)
4.10 Fundamental equations for time-harmonic electromagnetic fields (1; 23)
4.11 Relations between the fundamental equations for the electromagnetic field (1; 24)
5. Constitutive relations (2; 26)
6. Boundary conditions at motionless boundary between different media (4; 30)
7. Extension to electromagnetic phenomena of the principle of energy conservation:
7.1 Poynting's theorem; physical meanings of terms in the analytical formulation of Poynting's theorem (3; 32)
7.2 exercises: conversion of electromagnetic energy to mechanical or thermal energy and vice versa; Nichols disk; Joule effect in the presence of a direct current in a cylindrical conductor (2; 34)
7.3 Poynting's theorem for time-harmonic fields (2; 36)
7.4 exercises: dissipations due to Joule effect or viscous polarization; microwave ovens; antennas radiating in a homogeneous medium: interpretation in classical or photon terms; (3; 39)
8. Extension to electromagnetic phenomena of the laws of conservation of linear and angular momentum: theory, exercises and applications (3; 42)
9. Uniqueness theorems for electromagnetic fields: general and “time-harmonic” case; importance of boundary and initial conditions; electromagnetic boundary and Cauchy problems; formulation of problems of interest for guided propagation; formulation of electromagnetic radiation problems; formulation of electromagnetic “scattering” problems (6; 48)
10. Electromagnetic waves:
10.1 Electromagnetic fields in simple homogeneous media without charge carriers and impressed current densities: wave equation (1; 49)
10.2 Wave equation in one space dimension: general form of its solution (2; 51)
10.3 Progressive and regressive plane waves; their expressions for a generic direction of propagation (0.5; 51.5);
10.4 Electromagnetic plane waves: TEM waves; general expressions for the electric and magnetic fields; speed of light as the velocity of propagation of electromagnetic plane waves; an additional comment on the special theory of relativity (2; 53.5)
10.5 Other possible waves: spherical waves (0.5; 54)
10.6 Monochromatic plane waves; wavelength, wavevector, polarization of time-harmonic vectors and vector fields and its practical consequences (polarization division multiplexing, stereoscopic vision, etc.), skin depth (3; 57)
10.7 Some considerations on the effects of propagation in the presence of time-dispersive materials and on plane electromagnetic waves in the presence of simple discontinuity (3; 60).

The hours devoted to the individual topic and the sum of the hours devoted to the various topics are shown in parentheses, respectively.

This course, dealing with topics of scientific-technological interest such as electromagnetic fields, contributes to the achievement of the following Sustainable Development Goals of the UN 2030 Agenda:
8.2 (Achieving higher standards of economic productivity through diversification, technological progress and innovation, also with particular attention to high added value and labor intensive sectors)
9.5 (Increase scientific research, improve the technological capabilities of the industrial sector in all states - especially in developing countries - as well as encourage innovations and substantially increase, by 2030, the number of employees for every million people, in the research and development sector and expenditure on research – both public and private – and on development)

RECOMMENDED READING/BIBLIOGRAPHY

• S. Bobbio, E. Gatti, Elementi di elettromagnetismo, Bollati Boringhieri, 1991
• G. Conciauro, L. Perregrini, Fondamenti di onde elettromagnetiche, McGraw-Hill, 2003
• J. D. Jackson, Classical electrodynamics, Wiley, 1999
• D. Pescetti, Elettromagnetismo, Piccin, 1985

Handouts prepared by the course teacher are also available.

TEACHERS AND EXAM BOARD

LESSONS

LESSONS START

https://corsi.unige.it/8713/p/studenti-orario

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

The final exam is oral. All students will be asked three questions, of which at least one theoretical and one presented as an exercise.

ASSESSMENT METHODS

At the end of the course the student should show to have understood the basic principle of electrodynamics in the presence of charges in vacuum or in matter and to be able to solve simple problems.