PHYSIQUE 2 (T)
Aperçu des sections
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Matière : Physique 2
Unité d'Enseignement transversale: (UET)
Niveau : L1 Mathematique
Volume Horaire : 42 h (1H30 Cours +1H30 TD)
Crédit = 3
Coefficient : 2
Enseignant : Dr. Rachid CHADOULI
E-Mail : R.CHADOULI@univ-dbkm.dz
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Electricity is a natural phenomenon that can be used to power equipment and electronic devices.
Atoms are present everywhere in space, these atoms have electrons. Electricity is the flow of electrons from one atom to another. This flow is called "electric current". Atoms that easily exchange electrons are called conductors.
The History of Electricity
Humans have been using electricity for less than 300 years, the concept of electricity has been known for thousands of years, but it wasn't until the 1880s that this resource made its way into our daily lives. Adaptation to electricity enabled the second industrial revolution and paved the way for modern society.
Electricity Measurement
We measure electricity in watts. This name comes from James Watt, to whom we credit the invention of the steam engine.
The Origin of Electricity
Electricity sources fall into two categories:
· Renewable sources naturally renew themselves quite quickly, for example: nuclear, hydroelectricity, wind and solar energy.
· Non-renewable sources are exhaustible such as coal, oil and gas
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This course is intended for students in their first year of the bachelor's program in Mathematics
The course contains, with mathematical reminders at the beginning, four chapters:
Chapter I-part 1 : Electrostatics
Chapter I-Part 2: Gauss's Theorem
Chapter II: Conductors and Capacitors
Chapter III: Electrokinetics
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At the end of this course, the student will be able to:
· Identify the different physical quantities in electricity.
· Differentiate between laws for point loads and continuous load distributions.
· Apply Gauss's theorem to the field calculation.
· Differentiate between Ohm's law at the microscopic and macroscopic scales.
· Adapt Kirchhoff's laws to different types of circuits.
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Recommended prior knowledge:
- Basic notions of electricity.
- Know some simple experiments about general electricity and their explanations.
- Know a few basics about physics.
- Know the source of the electricity.
- Know some mathematical operators for field and electric force calculations.
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Evaluation Methods
Exam (60%) , contrôle continu (40%)
The exam will be held in person and not online -
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Electrostatics is a part of physics, more specifically electricity, that is concerned with the behaviour of permanent (time-invariant) and immobile (static) electric charges as well as the forces produced by their interactions, observable by humans in their environment.
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1-Electrostatic forces 2- Electric fields 3- Electric Potential 4-Electric Dipole 5-Gauss's theorem.1- Chapter 01..........Part01
2- Chapter 01..........Part II.....Gauss's theorem
3-TD N°01-Part 1
4-TD N°01+corrigé-Part 2
5-Ressources
7- Controle Continue 1
( le travail doit etre effectué et envoyé par email r.chadouli@univ-dbkm.dz avant 21-04-2024)
8- corrigé de la série TD 1
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Electrostatics is concerned with the behaviour of permanent (time-invariant) and immobile (static) electric charges as well as the forces produced by their interactions, which can be observed by humans in their environment.
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Understanding the origin of electrostatic phenomena
Know Coulomb's law and know how to apply it -
In this chapter, the student needs to have prerequisites in terms of:
Know some simple experiments about general electricity and their explanations
Vector calculus (dot product and cross product)
Presentation of vectors and geometric calculus (Pittagort's rule and trigonometry laws -
1- Total and partial influence 2- Calculation of capacities – Resistances – Laws 3- Generalized Ohm’s lawA conductor is a medium in which there are positive and negative charges that can move under the action of an electric field
A capacitor is an elementary electronic component, consisting of two conductive armatures (called "electrodes") in total influence and separated by a polarizable insulator (or "dielectric"). Its main property is that it can store opposite electrical charges on its armatures.
1- Chapter 2
2- TD 2
3- Corrigé de la série TD 2
4- Supplementaire
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Chapter 3
Electrokinetics is the study of the movement of charges. In other words, it is the study of electrical circuits and, above all, the study of the displacement of electricity in conductive material media, as opposed to electrostatics which studies the phenomena and laws relating to stationary electricity.
As the conductor is the medium where charges are able to move freely, we can mention metals, ionic solutions, semiconductors. In metals, only electrons move freely. In other environments, there are different carriers of moving charges, in the case of electrolytes with several positive and negative ions in the case of ionized gases.
1-Chapter 3
2-TD 3
3- Corrigé de la série TD 3
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1- Introduction
Magnetostatics is the branch of physics that studies magnetic fields in systems where the currents are steady (not changing with time). It is a subfield of electromagnetism, focusing on the behavior and properties of magnetic fields produced by constant currents.
Magnets have been known since ancient times as magnetite, a stone found in proximity to the city of Magnesia (Turkey). It is from this stone that the current name comes of magnetic field.
The Chinese were the first to use the properties of magnets, more than 1000 years ago, to make compasses. They consisted of a magnetite needle placed on top of straw floating on water contained in a graduated container.2- Magnetostatic force (Lorentz and Laplace)
In magnetostatics, the forces experienced by charged particles and current-carrying conductors in a magnetic field are described by the Lorentz and Laplace forces.
Lorentz Force
The Lorentz force describes the force on a charged particle moving through a magnetic field. It is given by:
F=q(E+v×B)
where:
- F is the force on the particle.
- q is the electric charge of the particle.
- E is the electric field.
- v: is the velocity of the particle.
- B is the magnetic field.
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In magnetostatics, we usually focus on the magnetic component of the Lorentz force, since the electric field component can be considered separately in electrostatics. Thus, the magnetic part of the Lorentz force is:
F=q(v×B)
This force is perpendicular to both the velocity of the particle and the magnetic field, causing the particle to move in a circular or helical path in the presence of a uniform magnetic field.
Laplace Force (Force on a Current-Carrying Conductor)
The Laplace force describes the force on a current-carrying conductor in a magnetic field. It is given by:
dF=I(dl×B)
where:
- dF is the differential force on a small segment of the conductor.
- I: is the current through the conductor.
- d: is a differential length vector of the conductor.
- B:is the magnetic field.
For a finite length of conductor, the total force is obtained by integrating along the length of the conductor:
This force is also perpendicular to both the direction of the current and the magnetic field.
Mathematical Examples
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Lorentz Force Example: A proton (charge q=+1.6×10^−19C) moving with velocity v= 10^6 m/s in the x-direction enters a magnetic field B= 0.1T in the z-direction. The force on the proton is: F=q(v×B)=(1.6×10^−19 C)(10^6 m/s i^×0.1 T k^) The proton experiences a force of 1.6×10^−14 N in the y-direction.
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Laplace Force Example:
- A wire carrying a current I=5I is placed in a magnetic field B= T perpendicular to the wire, over a length L= m. The force on the wire is Understanding the Lorentz and Laplace forces is crucial for designing and analyzing systems that involve the interaction of electric currents and magnetic fields, forming the basis for many modern technological applications.
3- megnetic fields
Magnetic Fields and Magnetic Flux:
A magnetic field B: is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials.
Magnetic flux ( Φ) : through a surface is the integral of the magnetic field over that surface.
4- Biot's law and Sawark
The Biot-Savart Law is a fundamental principle in magnetostatics that describes how steady electric currents produce magnetic fields. It is analogous to Coulomb’s law in electrostatics but applies to the magnetic field generated by currents.
It provides a mathematical model to calculate the magnetic field () at a point in space due to a small segment of current-carrying wire. The law is named after French physicists Jean-Baptiste Biot and Félix Savart, who discovered it in the early 19th century.
Significance
The Biot-Savart Law is essential for understanding the magnetic fields generated by currents in various geometries. It forms the basis for more complex calculations in electromagnetism and is foundational in the design of electrical devices such as motors, transformers, and inductors.
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