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## Sunday, April 17, 2022

### EMT - CHAPTER 11 - ELECTROMAGNETIC WAVES AND PROPAGATION (Teaching Videos)

CHAPTER 11: Electromagnetic Waves and Propagation

The objectives:

- To learn about the behavior of electromagnetic waves

- To learn the behavior of electromagnetic waves when interact with different media; conductor, dielectric (lossy / lossless), and free space.

- To learn about Poynting vector; to determine the power of electromagnetic field.

Part 2: Helmholtz Equation and Propagation of Plane waves:

- You will learn the basic concept of propagation for electromagnetic wave using derivation of Helmholtz equation. You can see how E-Field and H-field co-exist for time varying field and how we can express the wave in term of mathematical expression.

Part 2a: Helmholtz Equation and Propagation of Plane waves (Example):

- You will learn the basic concept of propagation for electromagnetic wave using derivation of Helmholtz equation. You can see how E-Field and H-field co-exist for time varying field and how we can express the wave in term of mathematical expression.

Part 3: Plane wave in Lossy Media:

In part 3, you will learn the behavior of plane wave when going through the lossy media (dielectric - Lossy). The example is also given for more explanation.

Part 4: Plane wave in Lossless and free space media:

In part 4, you will learn the behavior of plane wave when going through a lossless media (dielectric - Lossless) and free space.

Part 5: Plane wave in conductor:

In part 5, you will learn the behavior of plane wave when going through a conductor.

Part 6: Power and Poynting Vector

In part 6, you will learn to determine the power for electromagnetic wave using Poynting Vector.

### EMT - CHAPTER 10 - FARADAY'S LAW (Teaching Videos)

What we learnt so far is time invariant field. Starting in Chapter 10, we will see the case time varying field. The objectives of Chapter 10 are as followed:

1- To identify the difference between the static field (electric and magnetic field) with the time varying field.

2- To exhibit the phenomena whereby the current is produced by the time varying magnetic field, i.e: Faraday’s Law.

3- To investigate on the changes of Maxwell’s equation for time varying field (due to Faraday’s Law).

Part 1 - Introduction to Faraday's Law.

Part 2 - Three Conditions of Faraday's Law:

Induced EMF can be generated in three conditions; a static circuit in time varying magnetic field, moving circuit in time invariant magnetic field, and moving circuit in time varying magnetic field. We will see how we can do the analysis for all conditions.

Part 3 - Displacement Current.

For Time invariant current source, the current cannot pass through capacitor as it look like open circuit based on the construction of the capacitor which is two conductor separated by dielectric material.

However, the current exist when we supply the capacitor circuit with a time varying current source. The current is known as displacement current.

This Sub-topic will discuss how the displacement current can be derived by using continuity current equation as well as Maxwell equation.

Part 4 - Maxwell equation.

This part will summarize the 4 Maxwell equations that being the core for EMT. We also will see how Maxwell equation are used to derive the loss tangent for lossy dielectric material.

### EMT - CHAPTER 9 - MAGNETIC FORCE AND MATERIALS (Teaching Videos)

Chapter 9 discusses the principle of magnetic field acting on current carrying conductor Force is experience by the conductor carrying wire by 3 conditions that will be discussed later. We will also discuss the concept on inductor and magnetic energy stored inside the inductor.

For Part 1: Lorentz Equation.

You will learn how force are produced in current carrying conductor.

Part 2: Discuss how the magnetization occurred inside the magnetic materials via the exposed of external magnetic field. The term permeability is then introduced. There are 3 categorizes of materials need to be discussed in term of the tendency to be magnetized.

Part 3: Boundary Condition - This part will discuss the relationship between magnetic field from one material to another neighboring material. The relationship of magnetic field between two materials can be solved using boundary condition.

We will apply the Gauss's law for magnetic field to find the relationship between normal component and we can use ampere's law to determine the relationship between the tangential component.

In Part 4, we will cover the inductance and energy. Students will learn about magnetic linking flux and how it can be used to determine the inductance effect. There are two types of inductance which is self inductance (self generated) and mutual inductance (generated by another source of magnetic flux).

Students will learn how inductor can stored energy into its volume.

### EMT - CHAPTER 8 - AMPERE'S LAW (Teaching Videos)

In Chapter 7, you already learnt how to determine the magnetic field intensity using Biot Savart's Law. In Chapter 8, you will learn about Ampere's law to determine the magnetic field intensity. Ampere's law is a simple way to determine the magnetic field intensity compared with the Biot Savart's law. This is comparable with Gauss's law for electrostatic field. However, Ampere's law is only applicable for symmetrical field behavior.

PART 1 - Introduction

Students will be introduced with the concept of Ampere's law based on the current behavior.

Part 2:

Students will learn the analysis of magnetic field intensity for filament current and surface current.

Part 3:

This part, student will be introduced with the magnetic flux line, magnetic flux density, and the analysis of magnetostatics field intensity due to the volume current source.

Around the current source, there are magnetic field. The magnetic flux is actually a line of magnetic line around the source. The magnetic flux density is a measure of how dense the flux line that pass through the area.

Part 4 discusses the stokes theorem and curl, which is another method to determine the magnetic field intensity other than using Ampere's law. Stokes theorem solve the field integration along the closed surface that is equivalent to the field integration along the closed line.

Part 4 discusses the stokes theorem and curl, which is another method to determine the magnetic field intensity other than using Ampere's law. Stokes theorem solve the field integration along the closed surface that is equivalent to the field integration along the closed line.

Part 4b:

This part discuss an example related to how to solve the magnetostatics problem using stokes theorem and curl. In the end, you will see that the solution using stokes and curl will give the same answer as solving using ampere's law.

### EMT - CHAPTER 7 - BIOT SAVART'S LAW (Teaching Videos)

Chapter 7 is the beginning of magnetostatics. You already learnt about electrostatic field and their properties. Electrostatic field produced by static charge. However, when the charge started moving with constant velocity, it become direct current, and direct current is the source of magnetostatics field.

In Part 1, you will be introduced with current elements. The Magnetic field intensity can be produced by different current elements such as filament current current, surface current element, and volume current element. Here, we will initially introduced with the three different current elements.

For Part 2, you will be introduced with Filament Current Element. Filament current elements can produces magnetic field intensity around it. Using Biot Savart's law, we can find the magnitude and direction of the magnetic field around the filament current.

For Part 2, you already learnt about Filament Current Element. Filament current elements can produces magnetic field intensity around it. Using Biot Savart's law, we can find the magnitude and direction of the magnetic field around the filament current.

In Part 3 here, you will see how to determine the Magnetic Field Intensity for filament current elements using Biot Savart's Law.

For Part 4, you will see the analysis of magnetic field intensity produced by circular loop filament current using Biot savart's Law.

Part 5 shows the analysis of magnetic field intensity produced by Solenoid current using Biot savart's Law. Solenoid is a device constructed by having wire wound with many number of turns.

You already learnt from Part 1 - 5 about the current elements that contributes to magnetostatics field. To strength your understanding of this topic, please do this homework as you exercise.

## Saturday, April 16, 2022

### EMT - CHAPTER 6 - LAPLACE, POISSON, UNIQUENESS THEOREM (Teaching Videos)

From Chapter  1 - 5, you already learnt the concept of vector and coordinate and its important to solve electrostatic problem. You also learnt about coulomb's law and gauss's law to find Electric field intensity, Electric flux density as well as electric potential. In Chapter 6, you will be introduced with another approach to find electric potential as well as other electrostatic components by using Laplace or Poisson equation. To satisfy the solution, we need to apply uniqueness theorem.

For Part 1, you will be introduced with the concept of Laplace & Poisson as well as Uniqueness Theorem to solve the problem related to the Capacitance for different coordinate system.

For Part 2, you will be introduced to the method to solve Laplace equation (that satisfy the uniqueness theorem). The same method also can be used for Poisson's equation.

For Part 3, you will learn to solve the Laplace equation that satisfy the uniqueness theorem for Cartesian coordinate. The same method can be used to solve the Poisson's equation.

For Part 4, you will learn to solve the Laplace equation that satisfy the uniqueness theorem for Spherical coordinate. The same method can be used to solve the Poisson's equation.

For Part 5, you will learn to solve the Laplace equation that satisfy the uniqueness theorem for Cylindrical coordinate. The same method can be used to solve the Poisson's equation.

## Tuesday, April 12, 2022

### EMT - CHAPTER 5 - ELECTROSTATIC IN A MEDIUM (Teaching Videos)

Hello! For those who have followed my teaching video so far, we already learnt to find the electric field intensity for various charge systems but, in free space / vacuum. In Chapter 5, we will learn about Material. Materials can be classified into conductor, semi-conductor, and dielectric (insulator) based on the material conductivity on electric currents.

For part 1, you will be introduced to materials and the characteristics such as permittivity, permeability, and conductivity. Few things will be highlight such as Resistance of Conductors, boundary condition for dielectric-dielectric materials and Capacitance.

For part 2, you will learn the concept of convection currents. Convection currents can propagate in vacuum. It does not need conductor to flow. Therefore, convection current do not obey the Ohm's Law. There are three different currents that you will see in EMT. Two of it will be covered in this Chapter (convection current and conduction current) and other one (displacement current) will be covered in time varying field.

For part 3, you will learn how to derive a continuity current equation. Continuity current equation is important to explain the behavior of electric current in conductors. The concept of electric current is also discussed in the very fundamental way.

For part 4, you will learn about conduction current; a type of current that need a conductors to flow. The behavior of conductors when interact with external electric field will also been discussed. The formula derivation of current density is also shown.

For part 5, you will learn about resistance for conductor based on Ohm's Law. The resistance can be defined as a ratio between potential and currents.

For part 6, you will learn about materials, specifically dielectric materials. You will see what happened to the atom of dielectric materials when exposed with external electric field. Then, you will be introduced with the concept of bound volume charge density and bound surface charge density which only exist inside dielectric materials.

For part 6, you already learn about materials, specifically dielectric materials. Then, you also see what happened to the atom of dielectric materials when exposed with external electric field. Then, you has been introduced with the concept of bound volume charge density and bound surface charge density which only exist inside dielectric materials.

Here, an example of the related problem with part 6 will be discussed. You will see how to find the bound surface charge inside dielectric as well as to determine the bound volume charge.

For part 7, you will learn about Boundary Condition to relate the behavior of field inside in different mediums. When E and D field excited from one region to another region, the magnitude and direction will be changed. Basically, it obey Snell's Law as to explain the propagation of light inside glass coming from free space.

For part 7, you already learnt about Boundary Condition to relate the behavior of field inside in different mediums. When E and D field excited from one region to another region, the magnitude and direction will be changed. Basically, it obey Snell's Law as to explain the propagation of light inside glass coming from free space.

Here, in Part 7(b), We will discuss two examples related to boundary condition; both examples will show different coordinate systems. eg: Cartesian coordinate and cylindrical coordinate. It can also be spherical coordinate however, it will not be discussed here.

For Part 8 (Last Part) your will be introduced with a device called Capacitor. Capacitor is constructed using two metals and separated by dielectric material. Step by Step to find a capacitor is shown in this sub-topic including the example of problem.

### EMT - CHAPTER 4 - POTENTIAL (Teaching Videos)

Chapter 4 discusses about the concept of potential. There are three different potential that we will cover in this Chapter. Before that; we need to learn what is actually Potential / Electrical potential (Also known as Voltage) and how can we define and derive the potential?

In Part 1, we will discuss about energy. Then later on, you will see in other part that the energy can be used to derive the potential.

In Part 2, we will discuss about electric potential. You will see how we can find the electric potential between two points of interest. The analysis of electric potential can be in cartesian coordinate, cylindrical coordinate or spherical coordinate depend on the situation.

In Part 3, we will discuss one example about electric potential. You will see how we can find the electric potential between two points of interest. The analysis of electric potential can be in cartesian coordinate, cylindrical coordinate or spherical coordinate depend on the situation. This example shows the analysis in spherical coordinate.

In Part 4, we will discuss about Absolute potential. Absolute potential is basically a potential at certain point which its reference is at infinity. However, the reference point can also be somewhere else with given reference voltage.

In Part 5, you will see how to find absolute potential or potential different due to line charges and surface charges. Cylindrical coordinate and spherical coordinate are selected for the analysis.

In Part 6, you will see the relationship between electric potential and electric field intensity using potential gradient.

In Part 7 (Last Part), you will learn how to determine the energy in a Charge systems. The methods to determine the charge system depend on the charge behavior and the coordinate systems.

### EMT - CHAPTER 3 - GAUSS'S LAW (Teaching Videos)

In Chapter 3, You will learn another method to find the Electric Field Intensity using Gauss's Law. Gauss's Law is much simple compare to Coulomb's Law. However, it only applicable for symmetrical charge systems.

In Part 1, You will learn the concept of Gauss's Law. A new parameter will be introduced which is Electric Flux Density, D. We can see how we can relate the electric flux density with the charge system.

In Part 2, You will see few examples related to Gauss's Law.

In Part 3, You will learn the Divergence Theorem. Using Divergence, we can solve more complex problem in more simple way compared with Gauss's law.

### EMT - CHAPTER 2 - COULOMB'S LAW (Teaching Videos)

Coulomb's Law can be used to determine the intensity of Electric Field at certain point in a specific coordinate system. It is a universal Method that can be applied in various types of Charge Conditions.

In Part 1, you will be introduced with Points Charge and Line Charge Systems

In Part 2, you will be introduced with Surface Charge and Volume Charge Systems.

In Part 3, you will be introduced with Points Charge Systems with detail analysis using basic equation based on Coulomb's Law.

In Part 4, you will be introduced with the analysis of Line Charge System to determine the Electric Field Intensity produced by it.

In Part 5, you will be introduced with the analysis of Line Charge System in the form of circular loop to determine the Electric Field Intensity produced by it.

In Part 6, you will be introduced with the analysis of Surface Charge System to determine the Electric Field Intensity produced by it. Circular disk is selected due to its symmetrical behavior at all direction which make the analysis much easier compared with other shapes.

In Part 7, you will learn the detail analysis of Straight Line Charge System to determine the Electric Field Intensity produced by it.

## Monday, April 11, 2022

### EMT - CHAPTER 1 - VECTORS & COORDINATE (Teaching Videos)

Mathematical Preliminary: Vectors Analysis.

Vectors - one of the most important mathematical topics that will be used to solve problems related to EMT.

Vectors (Part 1) :

Vectors (Part 2) :

Mathematical Preliminary: Coordinate System.

Coordinate System is very important to explain the concept of EMT. When solving problem related to EMT, we need correct coordinate system to define it. Therefore, understanding coordinate system is Vital in this course.

Part 1 discusses the Cartesian Coordinate. You will learn the parameters involved with Spherical case (x, y, and z)

Coordinate System (Part 1):

Part 2 discusses the Cylindrical Coordinate. You will learn the parameters involved with Spherical case (radius, r, phi, and x/y or z)

Coordinate System (Part 2):

Part 3 discusses the Spherical Coordinate. You will learn the parameters involved with Spherical case (radius, r, theta, and phi)

Coordinate System (Part 3):