70/0005-M - PHYSICS 2
Academic Year 2021/2022
Free text for the University
ALESSIO FILIPPETTI (Tit.)
- Teaching style
- Lingua Insegnamento
|[70/75] BIOMEDICAL ENGINEERING||[75/00 - Ord. 2017] PERCORSO COMUNE||7||70|
Scope of Physics 2 is furnishing students with an introductory but rigorous knowledge of the fundaments of classical electromagnetism, which plays a paramount role in so many natural phenomena, and is at the core of our technological world.
Students are asked to become acknowledged with the language of physics laws, and to deeply penetrate the meaning of these laws and their relations with the observed phenomena. The bulk of knowledge acquired in the class will represent an essential cultural background from personal and professional viewpoints, and it will be essential to support students across their future, more specialized studies.
Knowledge and understanding.
At the end of the Class, we expect that students will have developed:
- the knowledge of the physical quantities at the fundament of the electromagnetism, their units of measurement, and the laws which rule their behavior, as well as the capability to give a correct interpretation to the meaning of these laws
- the capability to relate the laws of electromagnetism with the interpretation of the natural phenomena, and with the technological applications related to the electromagnetism, with special emphasis to applications inherent to biomedical engineering.
- an introductory knowledge of tools/devices at the basis of modern electronics, such as resistors, capacitors, inductors, coils, electrical motors, transformers.
Capability to apply knowledge and understanding.
At the end of the class we expect students to be able to:
- recognize the fundamental physical quantities and the related laws of classical electromagnetism, and properly discuss their meaning and their importance in the framework of natural phenomena and technological applications for whom they are basic.
- solve simple numerical and conceptual problems, related to fundamental electromagnetic phenomena, such as electric and magnetic field generations, their interactions with electric charges and currents, magnetic induction, electrical circuits with resistors, inductors, and capacitors, the electromagnetic waves and the laws of light propagation.
- recognize and make use of quantities and concepts at the basis of classical electromagnetism, when eventually encountered in future studies or even in the framework of their professional life.
Autonomy of judgement
At the end of the class students are expected to be able to autonomously select and evaluate the necessary information for the correct interpretation of a scientific problem related to the electromagnetism, and to figure out the best route to arrive at the solution, even including suited simplifications.
At the end of the class students are expected to have acquired a suited property of language, in relations to themes and arguments related to electromagnetism. They should be able to modulate the arguments and the concepts in order to be clearly understood by both technically acknowledged peoples, as well as by a general, non competent audience.
Capability to learn.
At the end of the class students are expected to have acquired a sufficient cultural background in electromagnetism and the mathematical tools related to it, to be able to autonomously deepen their own preparation on specific themes which may be encountered in futures studies concerning engineering or applied physics in general.
By University regulation, in order to take the Physics 2 exam, it is first required to have passed Physics 1.
From a substantial viewpoint, in order to follow and learn comfortably all the arguments of the class, the following basic knowledge is recommended:
- Fundamentals of Analysis: real-valued functions, integral and differential calculus in one and more dimensions, fundamentals of linear algebra, differential equations up to second order.
- Fundamentals of Geometry: volumes, areas, surfaces; vector operations in Cartesian spaces, scalar and vector fields, fundamental relations of trigonometry.
- Fundamentals of Physics: Cinematic of point motion; laws of classical dynamics; concepts of force, work, kinetic and potential energy.
The course spans a total of 70 hours, approximately divided in 50 hours of theoretical lessons, and 20 hour of exercises solved by the teacher at the blackboard.
The outline of the argument is the following:
Electric charges. Conductors and insulators. Coulomb’s law. Quantization and conservation of electric charge. Electric field. Electric field lines. Electric field due to a single charge and to a charge distribution. Motion of a charged particle in a uniform electric field. Electric flux. Gauss’s law and relation with Coulomb's law. Application of Gauss’s law to various charge distributions.
2 - Electric potential
Work, electric potential energy and electric potential. Equipotential surfaces. Electric potential due to a point charge, to a dipole and to a continuous charge distribution. Relation between the electric field and the electric potential. Electric field and electric potential in an isolated charged conductor.
3 - Capacitors
Capacitance. Capacitors. Planar, cylindrical, and spherical capacitors. Capacitors in series and in parallel. Energy stored in an electric field. Energy density of the electric field. Capacitors with dielectrics and dielectric constant. Energy stored in an electric field in the presence of a dielectric. Electric dipoles in dielectrics. Gauss’s Law in dielectrics.
4 - Circuits
Electrical current and current density. Electrical resistance and resistivity. Ohm’s Law and microscopic interpretation. Semiconductors and superconductors. Power and Joule’s effect. Electromotive force. Kirchhoff’s laws and their physical meaning. Resistances in series and in parallel. RC circuits and capacitive time constant.
5 - Magnetic field in vacuum
Magnetic force and magnetic field (Lorentz law). Magnetic force acting on a current-carrying wire. Torque acting on a current loop. Magnetic dipole moment. Biot-Savart law. Forces between two parallel currents and SI unit of current. Ampère’s law and applications. Magnetic field due to an infinite wire, an infinite solenoid, a toroid, and a coil.
6 - Electromagnetic induction
Electromagnetic induction and Faraday’s law. Lenz’s law and physical meaning. Motional electromotive force. Generators. Induced electromotive forces and electric field. Self-induction. Self-induction in a solenoid and in a toroid. RL circuits and inductive time constant. Energy stored in a magnetic field. Energy density of the magnetic field.
7 - Alternate currents, LC circuits.
The alternate current (AC): importance of AC current in long-distance transport of the electric current. The LC circuit: general characteristics, equations of the circuit, energy stored in the circuit. The AC current generator. Excerpts on RLC circuits. The transformer: general characteristics, equations of the ideal transformer.
8 - Electromagnetic waves
Spectrum of e.m. waves and main features of visible light. Generation of "macroscopic" e.m. waves. Oscillating LC circuits and analogy mechanics-electricity. Propagation of e.m. waves and plane waves. Energy carried by the electromagnetic waves and Poynting vector. Intensity and solar constant. Radiation pressure. Linear polarization and Malus’s law. Light speed in vacuum and in a dielectric medium. Reflection and refraction. Chromatic dispersion. Total reflection, limit angle and applications. Polarization due to reflection and Brewster law.
The course is developed according to a standard school approach (frontal lessons): each argument is introduced by some simple phenomenological evidences of popular interest (e.g. a natural phenomenon or a technological application) in order to highlight its impact in our everyday life; to the aim, the teacher can make use of projected images or movies.
Then, a formal description follows, developed and illustrated in detail at the blackboard; the theoretical developments and demonstrations are followed or alternated with practical examples or small problems, which can help students to better grab and fix the concepts in mind. While writing at the blackboard, the teacher also projects on the screen some previously prepared slides, with the key passages of the demonstrations and the exercises, in order to help students in following the lesson with the best possible comfort. These slides can be publically downloaded in pdf format by the Unica's teacher website.
The lessons are also coordinated with the tutoring activity, which runs in different hours and location; in these hours, the tutor help and support students in solve problems and exercises assigned by the teacher, or proposed by the students themselves, and purposely addressed to train students towards the solution of the written exam.
In summary, the course includes:
- 70 hours of frontal lessons, approximately separated in 50 hours of theoretical arguments and 20 hours of exercises solved by the teacher.
- 20 hours of tutoring activity, conceived as a supplementary homework time, where students can gather and practice problem solutions in groups, supported by the presence of an experienced tutor.
Verification of learning
Partial and final exams are written tests to be solved in 3/4 hours, including a number of 6/8 problems. Each problem focuses on a specific topic, and is composed by several connected questions, typically of increasing difficulty. This allows the teacher to evaluate in detail the level of understanding and the problem-solving ability of the student.
Most of the problems are numerical, and require a formal development and calculations. One or two problems may be conceptual, i.e. students are required (again in written form on a limited blank space) to describe a physics law, or to develop a demonstration.
A partial exam can be taken by the students at the half of the course; the format is similar to the final exam, with 3/4 numerical problems related to the first part of the program. Students participate to the partial exam on a voluntary basis. In order to encourage and stimulate the largest possible participation, before the partial exam several hours of lessons are spent by the teacher in practicing exercises, and a 'trial' exam is organized to make students accustomed with the actual format of the real exam.
In the first official exam date after the conclusion of the class, those students who took part to the first partial exam will be exempted from solving half of the problems; for them the final score will be the average of the two half-exams. Students who took the partial exam but are unsatisfied of the vote can decide to redo the whole exam; of course, in this case the vote of the first partial exam will be erased once and for all. It is understood that the vote of the first partial exam remains valid only for the first official exam date after the end of the class; since the second date students will be required to accomplish the whole exam.
The score is attributed on a strictly objective criterion: for each problem a maximum score is attributed, with the total summing up to 30. The maximum score of '30 e Lode' is attributed in case all problems are carried out with correct numerical solutions and clear formal development.
The number of official exams is defined according to the Faculty regulation.
- FUNDAMENTALS OF PHYSICS - Electromagnetism, Optics 7th Edition Authors: David Halliday, Robert Resnick, Jearl Walker Editor: Casa Editrice Ambrosiana - Distributed by Zanichelli Year: 2015 http://www.zanichelli.it/ricerca/prodotti/fondamenti-di-fisica-volume-2-elettrologia-magnetismo-ottica
- Slides prepared by the teacher with all the arguments and the exercises developed in the class are available in pdf format from the Unica's teacher website. In the same site, the exercises carried out during tutoring hours, as well as an archive with solved problems of previous exam sessions can be found.
Teacher receives students every week in his office on Wednesday from 15:00 to 17:00, or by e-mail appointment (firstname.lastname@example.org). The teacher office is at the Physics Department, first floor, Cittadella Universitaria di Monserrato.