ELECTRICAL ENGINEERING EDUCATION

CHAPTER 5: Electrostatic Field in a Medium

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.


PART 1 - Introduction to Materials

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.

https://youtu.be/RtauK-1B5RE


PART 2 - Convection Currents

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.

https://youtu.be/z68RUs1kNio


PART 3 - Continuity of Current

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.

https://youtu.be/5aNAhFYBLVg


PART 4 - Conduction Current

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.

https://youtu.be/0HQ5F622Jzw


PART 5 - Resistance

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.

https://youtu.be/JEu9S4-P8Y0


PART 6 - Materials

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.

https://youtu.be/5BB6hAA6c3E


Example of related problem:

https://youtu.be/S2fhwpQAQIY


PART 7 - Boundary Condition

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.

https://youtu.be/_X8aIQqpNOo

PART 7(b)- Boundary Condition (Examples)

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.

https://youtu.be/PLTZjf7gzgA


PART 8 - Capacitance

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.

https://youtu.be/SVxQnd2GXP4