How ELECTRICITY works - working principle

Summary

This video from theengineeringmindset.com delves into the fundamentals of electricity, explaining the atomic structure, the roles of conductors and insulators, and the behavior of electrons in a circuit. It covers the concepts of voltage, current, resistance, and how they interact within electrical circuits. The script also touches on electromagnetism, transformers, capacitors, and the difference between AC and DC electricity, providing a comprehensive introduction to the topic for engineering enthusiasts.

Takeaways

• 🌐 Everything is made of atoms, which are the building blocks of all materials.
• 🔬 Atoms consist of a nucleus with neutrons and protons, and electrons orbiting in shells outside the nucleus.
• ⚡ Electrons are negatively charged and are attracted to the positively charged protons, but they can move between atoms in conductors.
• 🚫 Insulators, like glass and rubber, do not allow electrons to move freely between atoms.
• 🔌 Conductors, such as metals, allow electrons to flow, which is essential for electrical circuits.
• 🔋 A closed circuit with a power source, like a battery, can force electrons to move in a specific direction.
• 💡 Electrons passing through components like light bulbs can produce light and heat.
• 🔊 Voltage is the force that pushes electrons through a circuit, similar to water pressure in a pipe.
• 🔍 A volt is defined as a joule per coulomb, measuring energy transfer per unit charge.
• 🔄 Current is measured in amperes, indicating the rate of electron flow, with one amp being one coulomb of electrons flowing per second.
• ⛔ Resistance in a circuit restricts electron flow, affected by factors like wire length, thickness, and material.
• 🧲 A coil of wire can generate a magnetic field, which can influence electron movement within the wire.
• 🔄 Transformers can transfer and alter voltage levels between coils, a key concept in power electronics.
• 🔌 Capacitors store electrical energy by separating positive and negative charges, releasing it when disconnected.
• 🔄 There are two types of electric current: AC (alternating current) and DC (direct current), differing in the direction of electron flow.

Q & A

What is the basic structure of an atom?

An atom consists of a nucleus containing neutrons (which have no charge) and protons (which are positively charged). Electrons (which are negatively charged) orbit around the nucleus in different layers called orbital shells.

Why are some materials better conductors of electricity than others?

Materials are better conductors if they have loosely bound electrons in their outermost shell, known as the valence shell. These free electrons can easily move between atoms, facilitating electrical conductivity. Metals are typically good conductors.

What role do insulators play in electrical systems?

Insulators are materials that do not have free electrons and therefore do not allow electricity to flow through them easily. They are used to surround conductive materials to prevent unwanted flow of electricity, keeping systems safe.

How does voltage relate to the flow of electrons in a circuit?

Voltage is the force that pushes electrons through a circuit, similar to pressure in a water pipe. Higher voltage means more force to move electrons, enabling more electrical flow. A volt represents one joule of energy per coulomb of charge.

What is an ampere and how is it measured?

An ampere, or amp, is a unit of electrical current that measures the flow of electrons. It represents one coulomb of electrons passing through a point in the circuit per second. A coulomb is approximately 6.242 billion billion electrons.

What is electrical resistance and how does it affect a circuit?

Electrical resistance is the opposition to the flow of electrons in a circuit. It varies with the material, length, and thickness of the conductor. Higher resistance means less current flow. Resistance causes heat and, in some cases, light when electrons collide with atoms.

What are the basic components and function of a transformer?

A transformer consists of two or more coils of wire (primary and secondary) placed close to each other but not touching. It transfers electrical energy between circuits, and can change voltage levels by varying the number of coils in the primary and secondary windings.

How does a capacitor function in an electrical circuit?

A capacitor stores electrical energy by separating positive and negative charges across two plates when connected to a power source. It releases this energy when the circuit requires it, providing a temporary power boost.

What is the difference between alternating current (AC) and direct current (DC)?

Alternating current (AC) changes direction periodically, like the ebb and flow of tides, and is commonly used in household power supplies. Direct current (DC) flows in one direction only, as seen in batteries and many portable devices.

Why are both AC and DC currents important in electrical systems?

AC is used for transmitting electricity over long distances due to its efficiency and ease of voltage transformation. DC is used in electronics and batteries, offering stable and consistent power. Both currents have specific applications and advantages in different contexts.

Outlines

00:00

🔬 Basic Principles of Electricity and Atomic Structure

This paragraph introduces the fundamental concepts of electricity, emphasizing the importance of understanding atomic structure for any engineering discipline. It explains that all materials are composed of atoms, which in turn are made up of protons, neutrons, and electrons. The nucleus contains neutral neutrons and positively charged protons, while negatively charged electrons orbit the nucleus in specific layers known as orbital shells. The paragraph further discusses how the valence shell, or outermost shell of an atom, contains electrons that can move freely, characterizing conductors like metals. Insulators, such as glass and rubber, are materials that do not allow free electron movement. The concept of a circuit, consisting of a path for electrons to flow between the terminals of a power source, is also introduced, along with the role of voltage in driving electron flow and the distinction between open and closed circuits.

05:02

🔋 Understanding Electrical Current, Voltage, and Resistance

The second paragraph delves into the specifics of electrical current, voltage, and resistance. It describes current as the flow of electrons, measured in amperes (amps), with one amp representing the flow of approximately six billion, 242 million, billion electrons per second. Voltage is explained as the driving force behind electron movement within a circuit, analogous to water pressure in a pipe, and is measured in volts, which is joules per coulomb. The paragraph also covers the concept of resistance, which restricts electron flow and is influenced by the material's properties and temperature. It mentions the use of resistors in circuits to control electron flow and protect components, and the generation of heat and light due to electron collisions with atoms, particularly in incandescent light bulbs. Additionally, it touches on electromagnetism, the creation of magnetic fields by coiled wires, and the principles behind transformers and capacitors, setting the stage for more advanced discussions in future videos.

10:02

🔌 Exploring AC and DC Currents and Their Applications

The final paragraph wraps up the video by distinguishing between alternating current (AC) and direct current (DC). AC is characterized by its periodic reversal of electron flow direction, akin to the tide, and is the standard for power distribution in homes and buildings. In contrast, DC flows in a single direction and is provided by batteries and used in handheld devices. The paragraph briefly mentions the ability to convert AC to DC and vice versa using power electronics, which is essential for charging devices and utilizing solar power in homes. It also hints at the historical context and advantages of both current types, suggesting a deeper exploration in future videos, and concludes with an invitation for viewers to ask questions and engage with the content creator's website.

Keywords

💡Atom

The atom is the basic unit of matter and the defining structure of elements. In the script, it's described as being composed of a nucleus containing neutrons and protons, with electrons orbiting around it. The atom is central to understanding electricity because it explains how materials can conduct or insulate, based on the behavior of electrons in their outermost shell, known as the valence shell.

💡Electron

Electrons are negatively charged subatomic particles that orbit the nucleus of an atom. The script mentions that electrons flow along orbital shells and can move between atoms in conductors, which is fundamental to the flow of electricity. The movement of electrons is what constitutes an electric current.

💡Nucleus

The nucleus is the central part of an atom, containing protons and neutrons. It is where the majority of an atom's mass is concentrated. As explained in the script, the nucleus is important because it holds the protons that attract electrons, influencing the atom's overall charge and its ability to conduct electricity.

💡Proton

Protons are positively charged particles found within the atomic nucleus. The script explains that the number of protons in an atom's nucleus determines the element's identity. Protons play a role in the attraction of electrons, which is essential for the conduction of electricity.

💡Neutron

Neutrons are neutral particles within the atomic nucleus, as mentioned in the script, they have no charge and contribute to the mass of the atom. While neutrons do not directly participate in electrical conduction, they influence the stability of the atom and thus can affect the properties of materials.

💡Valence Shell

The valence shell is the outermost electron shell of an atom. The script describes it as the shell where loosely bound electrons can be found, which can move to other atoms, making the material a conductor. Understanding the valence shell is key to grasping how materials can conduct electricity.

💡Conductor

A conductor, as explained in the script, is a material that allows electrons to flow freely between atoms. Metals are common conductors because they have free electrons in their valence shell that can move easily, enabling the flow of electric current.

💡Insulator

Insulators are materials that do not conduct electricity because they lack free electrons to move between atoms. The script mentions materials like glass and rubber as insulators, which are used to prevent the flow of electricity in certain directions, ensuring safety.

💡Voltage

Voltage, as described in the script, is the force that pushes electrons through a circuit, similar to water pressure in a pipe. It is measured in volts and is essential for creating an electric current. The script uses the example of a nine-volt battery to illustrate how voltage provides energy to the electrons.

💡Current

Electric current is the flow of electrons through a conductor. The script explains that the unit of measurement for current is the ampere (amp), which represents the flow of one coulomb of electrons per second. Current is central to the functioning of electrical circuits and devices.

💡Resistance

Resistance is the opposition to the flow of electric current in a circuit, as mentioned in the script. It is influenced by factors such as the material's properties, the length and thickness of a wire, and temperature. Resistors are components used in circuits to deliberately introduce resistance, which can be used to control current flow or generate heat and light.

💡Magnetic Field

A magnetic field is a region around a magnetic material or a current-carrying conductor where magnetic forces can be observed. The script explains that a coil of wire can generate a magnetic field, which can influence the flow of electrons within the wire. This concept is fundamental to the operation of electromagnets and induction motors.

💡Transformer

A transformer, as described in the script, is a device that uses coils of wire to transfer electrical energy from one coil to another, inducing a voltage in the process. Transformers are essential for stepping up or stepping down voltages in electrical systems, which is crucial for适配 the needs of different devices and safety.

💡Capacitor

A capacitor is an electronic component that stores electrical energy in an electric field. The script mentions that capacitors separate positive and negative charges across two plates, storing electrons until they can be released back into a circuit. They are commonly found in circuit boards and are similar to batteries in their function of storing energy.

💡AC and DC

AC stands for Alternating Current, and DC stands for Direct Current. The script explains that AC is the type of current where the flow of electrons periodically reverses direction, like the tide, and is commonly used in homes and buildings. DC, on the other hand, flows in one direction only, as provided by batteries. The script also touches on the conversion between AC and DC, which is necessary for devices like solar panels to power homes that require AC.

Highlights

Basics of electricity are essential knowledge for any engineering field.

Atoms are the building blocks of all materials, differentiated by their atomic structure.

Electrons orbit the nucleus at nearly the speed of light within orbital shells.

The valence shell contains loosely bound electrons that can move to other atoms.

Conductors allow electron flow, while insulators restrict it, such as metals and glass respectively.

Combining conductors and insulators safely directs electron flow in electrical devices.

Voltage in a circuit acts as a pushing force for electrons, analogous to water pressure in a pipe.

A volt is defined as a joule per coulomb, relating energy to the flow of electrons.

Current measures the flow of electrons, with one ampere equaling one coulomb per second.

Resistance in a circuit restricts electron flow, influenced by material properties and temperature.

Resistors are used in circuits to control electron flow for protection or to generate light and heat.

Magnetic fields generated by current passing through a coil can affect the flow of electrons.

Electromagnets and induction motors work on the principle of magnetic fields affecting electron flow.

AC generators work by inducing voltage in a wire through a magnetic field.

Transformers can adjust voltage levels by changing the number of coils in primary and secondary circuits.

Capacitors store electric charge and can release it when disconnected from a power supply.

Alternating Current (AC) and Direct Current (DC) differ in the direction of electron flow.

AC is commonly used in homes and buildings, while DC is provided by batteries and solar panels.

Power electronics can convert AC to DC and vice versa, enabling diverse applications.

Transcripts

Hey there, guys, Paul here

from theengineeringmindset.com.

In this video, we are going to be looking

at how electricity works.

Now, this is pretty essential knowledge

for any engineering, so we'll run through the basic parts

of what you need to know.

So let's start at the very basics

and for that, we need to take a look at the atom.

Everything, including you, is made from atoms.

All the materials we use are made from atoms.

The materials are just different

because the construction of their atoms

are slightly different.

The atoms are made from three particles,

two of which are found inside the nucleus

and the third particle sits outside this.

At the center of the atom, we have the nucleus.

Inside the nucleus, we have the neutrons,

which have no charge, and we also have the protons,

which are positively charged.

The neutrons and the protons are much heavier

than the electrons so these will stay within the nucleus.

Surround the nucleus are different layers of orbital shells.

These are like flight paths for the electrons.

The electrons flow along these flight paths

much like a satellite orbits our plant,

except that the electrons travel

at almost the speed of light.

The electrons are negatively charged

and they are attracted to the positive charge

of the protons.

The electrons orbit around the nucleus

in these orbital shells and there are a set numbers

of how many electrons can be in any one orbital shell.

The number of protons, neutrons, and electrons an atom has

tells us which material it is.

Atoms hold on to their electrons very tightly,

but some materials will hold on to them more tightly

than others.

The outer-most shell is known as the valence shell,

and in this shell,

some materials have loosely bound electrons

which can flow to other atoms.

Atoms which can pass electrons are called conductors

and most metals are conductors.

On the other hand, atoms which do not have free electrons

and so they can't pass electrons between other atoms

are known as insulators.

And these are things like glass and rubber.

Now, we can combine these materials

to safely use electricity

by having the conductor in the center,

which allows electrons to move,

but surround this with an insulator

to restrict where they can flow to,

i.e., not lead to us, which keeps us safe.

If we look inside a slice of copper cable

at the free electrons surrounding the nucleus

of the copper atom, you'll see that the free electrons

are able to move to other atoms,

but this happens randomly in any direction.

If we then connect this slice of copper cable

to a closed circuit with a power source,

such as a battery, then the voltage will force the electrons

to move and these will then all flow

in the same direction to try and get back

to the other terminal of the battery.

When I say circuit, this just means the root

which electrons could flow along

between the two terminals, the positive and the negative,

of a power source.

So we can add things into their path,

like light bulbs, and this means that the electrons

will have to pass through this in order to get

to the other terminal.

And so we can use this to create things such as light.

The circuit can either be open or closed.

In a closed circuit, that means the electrons

can flow around.

And in an open circuit, this means that the electrons

are not able to flow.

Voltage is a pushing force of electrons within a circuit.

It's like pressure in a water pipe.

The more pressure you have, the more water can flow.

The more voltage you have, the more electrons can flow.

But what does a volt mean?

Well, a volt is a joule per coulomb.

And a joule is a measurement of energy or work

and a coulomb is a group of flowing electrons.

We'll have a look at what a coulomb is

in just a second though.

So a nine volt battery can provide nine joules

of energy in the form of work or heat

per group of electrons that flow

from one side of the battery to the other.

In this case, the current of electrons

flow from one side of the battery

through the LED light bulb, which produces light,

and then the electrons flow to the other side

of the battery, therefore, nine joules of light

and heat is produced by the light bulb.

Current is the flow of electrons.

When a circuit is closed,

it means electrons can flow, and when the circuit is open,

no electrons will flow.

We can measure the flow of electrons

just like you can measure the flow of water through a pipe.

To measure the flow of electrons,

we use the unit of amp.

One amp means one coulomb per second

and one coulomb is a group of electrons.

The group is incredibly large and is approximately

six billion, 242 million, billion electrons,

and that has to pass in one second

for it to equal one amp.

That's why electrons are grouped together

and just called amps, to make it easier for engineers.

Resistance is a restriction to the flow of electrons

in a circuit.

The wire which carries the electrons

will naturally have some resistance.

The longer the wire, the greater the resistance.

The thicker the wire, the lower the resistance.

Resistance to the flow of electrons

is different for each material.

And the temperature of the material

can also change resistance to the flow of electrons.

Electrical circuits use specially designed components

known as resistors to purposely restrict the flow

of electrons.

This is either to protect other components

from too many electrons flowing through it

or it can also be used to create light and heat,

such as in an incandescent light bulb.

Resistance occurs when electrons collide with atoms.

The amount of collisions is different from one material

to another.

Copper has very low collision rate,

but other materials such as iron

will have much more collisions.

When collisions occur, the atoms generate heat

and at a certain temperature,

the material will then start to produce light

as well as heat, which is how the incandescent lamps work.

When a wire is wrapped in a coil,

it will generate a magnetic field

as the current passes through it.

The cable will naturally create electromagnetic field

by itself.

It's just intensified by the coil.

By wrapping it in a coil,

the magnetic field becomes so strong

that the magnetic field starts to actually

affect the electrons within the wire.

But we'll look at why this occurs

in a future, more advanced video.

We can increase the strength of the magnetic field

simply by wrapping the coils around an iron core.

We can also increase the number of turns within the coils

and also we can increase the amount of current

passing through the circuit.

And this is how electromagnets work

and it's also the base of how induction motors work.

If you want to learn more about induction motors,

we've already covered this in another video already.

Just see the link on the screen now.

And when a magnetic field passes across the coil of wire,

it will induce a voltage in that wire

caused by an induced electromotive force,

which is pushing electrons in a certain direction.

If the wire is connected in a circuit,

then this electromotive force will cause a current to flow.

This is the basis of how AC generators work

and the electricity at your wall sockets within your home

is produced in a very similar way.

Transformer, now, we can combine all of the aspects

together that we've just covered

and when we do so, we will see that we can use one coil

to generate electricity

and then we can place two other coils

in very close proximity to each other but not touching,

and this will create a transformer.

The transformer will induce a voltage

from the first of the primary coil

over into the secondary coil.

And this will force electrons to flow

if the coil in the secondary side

has a closed circuit.

Now what's important about the transformer

is that we can increase or decrease the voltage

between the primary and the secondary coils

simply by changing the amount of coils on either side.

Again, this is a subject all by itself

so we'll cover this in a more advanced video later on.

Now, something else which I just want to briefly mention

is the capacitor.

So, a capacitor forces positive and negative charges

to separate across two plates

when it is connected to a power supply.

This causes a build-up or store of electrons

within an electric field.

When the power supply is cut or interrupted,

these charges will then be released,

flow up, and meet again.

This provides a power source but only for a few seconds

until the charges have paired back up again.

It's slightly similar to a battery,

but capacitors are very common

and they're in almost every single circuit board.

We'll cover this obviously in more detail

in a future video.

Just be aware of these.

So the last part I want to cover in this video

is that there are two types of current electricity.

That being alternating current, or AC,

and then direct current, or DC.

Alternating current simply means

that the current flows backwards and forwards

in a circuit as the terminals are constantly reversed.

This is a bit like the tide of the sea.

It goes in and out, in and out, in and out.

So there is reversing constantly.

Now, alternating current is the most common source

of power and the plug sockets in your homes,

in your buildings, in schools, and work places, et cetera,

these will all be providing alternating current, AC.

Now, on the other hand, we've got direct current, or DC,

and that simply means that the current flows

directly in only one direction.

It is not alternating.

This is what's provided from batteries

and almost all your handheld devices

are from this, as well.

So we can convert AC to DC and vice versa

using power electronics.

And this is how we charge and power,

you know, small devices,

and it's also how solar panels can be used

to power our homes.

Because solar panels produce DC power

and our homes need AC power.

So we have to convert this for it to be usable.

So both AC and DC have pros and cons to it,

but, you know, for sure we'll look at this

in another later video.

It's a bit more advanced.

And there's also quite an interesting history

behind why we use AC, DC, and the inventors behind that.

If you've got 10 minutes, I definitely recommend

having a Google or a YouTube of this, too.

All right, that's it for this video.

Thank you very much for watching.

I hope you enjoyed this and it helped you.

If you have any questions,

please leave me in the comments section below.

Also don't forget to subscribe and check out our website,

theengineeringmindset.com.