Fundamental Physics/Electromagnetism

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Fundamental Mathematics | Fundamental Physics | Fundamentals of chemistry | Electricity | Electric Heat | Electromagnetism | Electronics | Electric circuit

It is necessary to revise the following mathematical concepts as they are used throughout this course:

Introductory Material[edit]


Electric charge
Electric charge Charge process Charge quantity Electric field Magnetic field
Negative charge O + e -> - - Q -->E<-- B ↓
Positive charge O - e -> + + Q <--E--> B ↑
Electric charge interaction
Coulomb law . Like charges repel, different charges attract . Negative charge attracts positive charge . The force of attraction negative charge attracts positive charge is called Electrostatic force can be calculated by Coulomb law as follow
Ampere law . The force that sets electric charge in motion from stationary state is called Electromotive force can be calculated by Ampere law as follow
Lorentz law . When electric charge interacts with magnetic field of a magnet, the magnetic force of the magnet will make electric charge to move perpendicular to the initial moving direction . The positive charge will move up, the negative charge will move down . The force of magnetic field that sets electric charge to move perpendicular to the intial moving direction is called Electromagnetomotive force can be calculated as follow
The sum of 2 forces Electromotive force and Electromagnetomotive force creates Electromagnetic force

Electrostatic field

The force of attraction of 2 different charges


The electric field of the charge in motion

Electric Potential

The potential of the electric field




Configuration Magnetic Field Magnetic field intensity
For a straight line conductor
circular magnetic field surrounds a point charge along the straight line
For a circular loop conductor
Magnetic field of wire loop.svg
circular magnetic field surrounds a point charge along the circular loop
For a coil of N circular loops conductor
lines of magnetic field runs from North pole (Positive polarity) to South pole (Negative polarity)

Electromagnetic induction[edit]

Electromagnetic induction takes place in a circular loop and a coil of N circular loops . According to Faraday, change in magnetic field will produce electric potential

For a single circular loop Magnetic field of wire loop.svg
Coil of N circular loops



The way a coil of N circular loops turn metal inside the loops into a electromagnet

Maxwell's equation

Electromagnetism of a straight line conductor[edit]


Electromagnetism of a circular loop conductor[edit]

Magnetic field of wire loop.svg

Electromagnetism of a coil of N circular loops[edit]

Basic Inductor with B-field.svg Electromagnet

Electromagnetic induction

Electromagnetic oscillation

Onde electromagnetique.svg Electromagnetic wave

Electromagnetic wave equation

Electromagnetic wave function

≈≈≈ Electromagnetic wave radiation


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