MAT 1023 : AUTOMOTIVE

ELCTRICAL AND ELECTRONIC

CHAPTER 1 : PRINCIPLES OF ELECTRICITY

PRINCIPLES OF ELECTRICITY

Fundamental of material

Substance Element Atom

Electricity :

Electricity can be defined as the movement of electrons

from atom to atom.

This can be happen only in a conductor and

not in insulator.

It can translate in ELECTRON THEORY.

WHAT IS ELECTRICITY

PRINCIPLES OF ELECTRICITY

PRINCIPLES OF ELECTRICITY

Occurrence of electricity

Material Molecule Atom Atomic nucleus Nucleus

Proton

Electron

PRINCIPLES OF ELECTRICITY

Electron Nucleus

Shell

Electrons

Protons

Neutron

+ +

+

-

Electrons

Structure of Atom Detail structure of Atom

Structure of Atom

PRINCIPLES OF ELECTRICITY

Atom ion

Electrically Neutral

Positive Ion Negative Ion

PRINCIPLES OF ELECTRICITY

Free Electron Movement = Occurrence of electricity

+ +

+

- -

-

-

- -

- -

- -

PRINCIPLES OF ELECTRICITY

Characteristic of magnetic substance and Magnetic line of force

◆ Magnetic line of force comes out from N pole and enter into S pole.

◆ Direction of magnetic line of force indicates the direction of the

magnetic field.

◆ Density of magnetic line of force(Density of magnetic flux) indicates strength of magnetic field

◆ Magnetic lines of force does not cross each other.

◆ If the direction of magnetic lines of force is same, those magnetic lines repel each other.

Magnetism & Electromagnet

PRINCIPLES OF ELECTRICITY

Magnetism

These figure show the magnetic field of attracting and repelling magnets.

The earth is a large magnetic, surrounded by a magnetic field.

PRINCIPLES OF ELECTRICITY

Magnetism

Current

Iron pieces

wire

Battery

PRINCIPLES OF ELECTRICITY

Electromagnet

◆ The law stated that whenever there is an

induce (influence) electromotive force

(emf) in a conductor, it is always in such a

direction and the amount of emf will

change accordingly .

PRINCIPLES OF ELECTRICITY

Electromagnetism ( LENZ’S LAW )

Current in

Current out S

N

PRINCIPLES OF ELECTRICITY

Electromagnet

PRINCIPLES OF ELECTRICITY

EMF – is generated in many ways

EMF

• Electromotif force is required whenever we want to move electron

Electromotif force

• Friction

• Chemical

• Heat

• Light

• Magnetism

• Pressure

PRINCIPLES OF ELECTRICITY

EMF – is generated in many ways

EMF

• Friction

PRINCIPLES OF ELECTRICITY

EMF

• Chemical

Electrolyte

Conductor

+ -

- + -

-

-

-

+

+

+ +

+

+

+

+

-

-

-

-

- -

-

- -

-

-

-

-

- -

-

- - -

-

- -

-

-

- Electron

+ Atom minus electron

Neutral atom

PRINCIPLES OF ELECTRICITY

EMF

• Heat

PRINCIPLES OF ELECTRICITY

EMF

• Light

•Pressure

EMF

+

-

+

- -

- - - -

-

-

-

- -

CRYSTAL

+ + + +

PRINCIPLES OF ELECTRICITY

PRINCIPLES OF ELECTRICITY

• Magnetism

EMF

+

-

-

-

-

-

-

-

+

-

-

-

-

-

-

-

S S N N

PRINCIPLES OF ELECTRICITY

Shells

12 Electrons (-)

Aluminum Atom

K

L

(K, L, M, N….)

CONDUCTOR

M

Any material which allows the free flow of electrons

PRINCIPLES OF ELECTRICITY

Shells

6 Electrons (-) oxygen

K

L

(K, L, M, N….)

• Any material which will not allow the free flow electrons

M

INSULATOR

PRINCIPLES OF ELECTRICITY

SEMICONDUCTOR

What’s semi-conductor

◆ Semi-Conductor :Material

which has the middle amount

of fixed resistance value

between conductor and non-

conductor

Junction of Silicon atom

Si Si Si

Si

Si

Free Electron

Silicon

PRINCIPLES OF ELECTRICITY