How electricity is generated for children. Electricity, where does it come from and how does it get to our homes? What to do to avoid these cuts

Cognitive journey-acquaintance "Electricity and electrical appliances"

Krivyakova Elena Yuryevna, teacher of the speech therapy group, MBDOU child development center - kindergarten No. 315, Chelyabinsk

Description:

Your attention is invited to the scenario of cognitive travel. Section "Child and the world around". The scenario of the cognitive journey is aimed at expanding and generalizing knowledge about electricity and electrical appliances, education safe behavior in relation to electricity and electrical appliances, interest in objects around everyday life, the use of acquired knowledge in gaming activities. The prepared material will be useful for teachers of additional education, educators of speech therapy and general education groups.
Integration of educational areas:"Cognition", "Communication", "Security", "Socialization".
Types of children's activities: playful, cognitive, communicative, experimental.
Target: Development of interest in phenomena and objects in the surrounding world. Expanding knowledge of safe behavior.
Tasks
Educational:
1. Expand knowledge about electricity and electrical appliances.
2. Summarize children's knowledge about the benefits and dangers of electricity.
3. Fill up the children's dictionary with new concepts of "hydroelectric power station", "battery", "electric current".
Correction-developing:
4. Activate the speech and mental activity of children. To promote the ability to clearly and competently articulate their thoughts.
5. Automate sound pronunciation in children with onomatopoeia.
6. Develop visual and auditory attention, verbal-logical thinking, memory, creative imagination.
7. Develop children's social and communication skills in joint activities.
Educational:
8. Cultivate a friendly attitude towards peers through the ability to listen to a friend and accept the opinion of another.
9. To develop elementary skills of safe behavior in everyday life when handling electricity.
Expected Result: increasing interest in surrounding objects in everyday life and using the knowledge gained in everyday life.
Preliminary work: conversation "Journey into the past of an electric light bulb"; memorizing riddles and poems about electrical appliances; viewing illustrations depicting electrical appliances; selection of items powered by batteries, accumulators, batteries for the exhibition; children's stories from personal experience.
Equipment:
- a split picture depicting an electric light bulb;
- cards from the didactic game "Evolution of transport and things around us" using the example of a group of "lighting devices";
- candle;
- multimedia system;
- a toy set for conducting experiments in different branches of knowledge "Electric Siren" from a series of scientific toys "We study the world»;
- exhibition of items powered by batteries, accumulators, batteries;
- easel;
- soft modules;
- models depicting safety rules when working with electrical appliances;
- emblems with the image of a light bulb according to the number of children.
Methods of training and education: artistic word (poems and riddles), demonstration material, use of TRIZ technology elements (techniques: “good - bad”, modeling), experimentation.
Terms and conditions: a spacious hall in which you can move freely; chairs according to the number of children; the table on which the exhibition is located; easel with inverted models of safe handling of electrical appliances.

The severity of the accident depends on. Tension: the higher it is, the higher the risk. Humidity and isolation of the body, the resistance of the body is weakened if the skin in contact with the current is wet, if the soil is wet, and the victim is barefoot. For example: contact with 220 V with dry or gloves, feet on dry ground, causes only tingling. If the hands and feet are bare and wet, there is a risk of cardiac arrest.

In recent days, without intention, we have all set a record in France. This is the largest amount of electricity! This phenomenon has a name: it is called peak energy consumption. This week it has reached an incredible amount. It also delighted many people who feared power outages.

Event progress:

Introductory word of the educator (stimulation for upcoming activities):
Dear Guys! I am glad to see you all healthy and cheerful. Today we are waiting for an unusual journey, in which we will learn a lot of interesting things. And for starters...
Problem situation: pay attention to what is on the table? It looks like they are cut pieces of the picture. Take one part each, try to put together the big picture (children collect).
What happened? (electric lamp).

Educator: Tell me, have people always used light bulbs for lighting? (children's answers).
Dive into the problem: I suggest you plunge into the past and trace how people illuminated their homes at different times.
Didactic game "Evolution of things around us"

What is the maximum power consumption?

Because this week, on Tuesday and Wednesday, France broke twice, the record for the most electricity consumed. To understand what corresponds to this peak, we must remember that all of our electrical devices need power to work. This amount of electricity is measured in watts, for example a TV consumes 200 watts every time you turn it on. If you count everything used by all electrical appliances at that time of day, you get a number: electricity consumption in France.

Exercise: Before you are pictures of different lighting fixtures. Choose a picture that caught your attention and you liked it. And now, with their help, we will build a path from the past to the present. (Arrange the cards in chronological order, in accordance with the previous conversation: “Journey into the past of the light bulb”).
Educator: We have built a bridge from the past to the present. I will now take a candle, light it, and you follow me. (the child walking last collects pictures). We cross the "bridge" from the past to the "present".
Educator: Here we are in the present (the teacher invites the children to sit on chairs in front of the screen).
Riddle-poem:
I see an outlet up on the wall
And it becomes interesting to me

(Electricity)
Educator: Do you want to know how electricity comes to our house?
slide show

Why are we breaking records now?

At this point, that figure surpasses all records. Because during the week it is cold all over France. So to keep our homes warm, we push the radiators all the way.

What time does this peak occur?

Meanwhile: at 19 Normal, that's when most people go home.

Will the peak justify the risk?

Yes, it's a power failure! In fact, it's simple: in France, electricity is mainly produced by nuclear power plants, thermal power plants and dams. All of these facilities produce watts in limited quantities. If we exceed the available amount, we risk causing huge power cuts.

The teacher comments: This is a hydroelectric power plant. Under high pressure, water enters the turbine, where electricity is generated using a generator. It is supplied to special substations, and from them it then runs along wires to our homes, hospitals, factories and places where people cannot do without electricity.
Educator: Tell me, why do people still use electricity, besides lighting the room? (suggested answer of children: to use electrical appliances).
Game "Riddles-riddles"
Children take turns guessing riddles. After the children's answers, the correct answer appears on the multimedia screen.
1st child:
I see dust - I grumble,
I'll finish and swallow! (Vacuum cleaner)
Educator: What sounds can we hear when the vacuum cleaner is running? (J)
2nd child:
First load the laundry into it,
Pour the powder and plug it into the socket,
Do not forget to set the washing program
And then you can go to rest. (Washing machine)
Educator: What sounds do we hear when the washing machine is running? (RU).
3rd child:
Wrinkled dress? Nothing!
I'll smooth it out now
To work for me, not to get used to ...
Ready! Can be worn. (Iron)
Educator: What sounds can we hear while the iron is running? (PSh).
4th child:
Live there different products,
Cutlets, vegetables and fruits.
Sour cream, cream and sausages,
Sausages, milk and meat. (Fridge)
Educator: Well done, you and I not only solved all the riddles, but also remembered all the sounds that we hear when these electrical appliances are working.
I wonder what sounds we hear when the refrigerator is running? (answer DZ).
Guys, remember what electrical appliances we have not yet named, name them. (Children's answers are accompanied by a slide show). Did everyone remember?
Physical education minute (activation of attention and motor activity, restoration of working capacity).
Educator: Where is the refrigerator usually located in the apartment? (in the kitchen)
And we will imagine that we are in the kitchen (children perform movements in accordance with the text).
What's the noise in this kitchen?
We will fry cutlets.
We'll take a meat grinder
Let's quickly check the meat.
Beat together with a mixer
Everything we need for the cream.
To bake a cake soon
We turn on the electric stove.
Electrical appliances are amazing!
It would be hard for us to live without them.
Educator: Do you guys know that people have learned to tame electricity, and even hide it in special "houses": accumulators and batteries - they are called "batteries" (Show pictures on the slide).
Experiment (specially prepared table). Now we will conduct an experiment with you and check: is it true that the electrical system can operate on conventional batteries. And make sure that they really "live" electricity (Experiment with the "electric siren" set).

Educator: Guys, who knows where else people use these "houses" to store electricity: batteries, accumulators? (Answers: video camera, flashlights, control panel, camera). The teacher draws the attention of children to the exhibition, examine the exhibits.
Educator: Guys, think about it and tell me what benefits electricity brings to a person? (children's answers).
- Is there any harm? (children's answers).
Rules for safe handling when working with electrical appliances
Children sit down on soft modules opposite the easel.
Exercise: Using the models, we need to formulate the basic safety rules when working with electrical appliances. By showing the models, we formulate the rules.

In France, you should know that there are three places that are more vulnerable than others in terms of the risk of breakdown: Brittany, Alpes-Maritimes and Var, because in these corners the high-voltage power lines do not produce electricity. there is still enough electricity compared to local needs. So, if you live in these areas, beware of cuts!

What can be done to avoid these cuts?

Since none of us can interfere with the weather, there are other tricks, such as adding a large sweater or wrapping more under the duvet. The word has several possible meanings: it is a kind of pickaxe or peaked mountain. But it can also be used in certain expressions such as "you are right" which means you will come at the right time to resolve a misunderstanding or problem. Finally, "peak" is used to talk about when a phenomenon reaches its maximum.

Rule 1 Do not stick foreign objects, especially metal ones, into the electrical outlet!
Why? Because the current, like a bridge, will move over the subject on you and can greatly damage your health.

Rule 2 Do not touch bare wires with your hands!
Why? An electric current flows through a bare wire that is not protected by a winding, the impact of which can be fatal.

Rule 3 Do not touch the switched on devices with bare hands!
Why? You can get an electric shock because water is a conductor of electricity.

For example, at the moment we say that we have reached the peak of electricity consumption, because we have never consumed so much electricity in France. Yes, lose negative charges so there are more positive charges left! The atom is positively charged.

Is there static electricity in nature?

Conversely, when an atom wins an election, it becomes negatively charged. If you have ever seen a thunderstorm and seen lightning, then you have witnessed the largest sparks created by static electricity in the air. For lightning, this stimulates the production of static electricity.

Rule 4 Do not leave the included electrical appliances unattended!
Why? Because the included electrical appliances can cause a fire. When leaving home, always check whether the lights are out, whether the TV, tape recorder, electric heater, iron and other electrical appliances are turned off.
caregiver reads a poem:
ELECTRICITY
I see a socket down on the wall
And it becomes interesting to me
What kind of mysterious beast is sitting there,
Our devices to work orders?
The animal's name is electric current.
It's very dangerous to play with him, my friend!
Keep your hands away from the current.
Do not rush to put your fingers in the socket!
If you try to joke with the current,
He gets angry and can kill.
Current - for electrical appliances, understand
Better never tease him!
Summing up the educational journey.
So our journey ended - acquaintance with electricity and electrical appliances. What did you like and remember especially in our trip? (children's answers). I wish you to remember the importance of electrical appliances in our lives and not to forget about the insidiousness of electricity. Remember the safety rules for using electrical appliances. And such a cheerful electric light bulb - an emblem will remind us of our journey.

The teacher distributes to the children an emblem depicting an electric light bulb.

All matter is made up of tiny particles called atoms. Inside the atom there are even smaller particles: electrons revolving around the center, or nucleus. The nucleus is made up of protons and neutrons. An electron has a negative charge and a proton is positive. Usually, an atom has as many electrons as it has protons, so the atom is neutral, that is, it has no charge. But sometimes electrons fly out of their orbits - they are attracted to other atoms that have a positive charge, because they do not have enough electrons.

The movement of electrons from one atom to another creates an energy called electricity. The electricity that we use is generated by giant machines - generators, and this happens in places called power plants. In order for the generators to work, a source of energy is needed. To produce the steam that will turn huge turbine blades that power a generator, water is heated to produce steam using heat generated either by burning coal, oil, or natural gas, or by fissioning nuclear fuel.

Light static electricity

There comes a time when the imbalance of fees is so important that it must stabilize! This load update causes lightning.

For this it is easy to make a home experience, we will need

Balloon Wool sweaterA ceiling. . Place the ball under the ceiling. My explanations for this are easy to do at home. Why doesn't the balloon stick to the ceiling? At the beginning of this simple experiment, you can check if your left ball is in the ceiling.

This will allow us to test its electrical charge. As you can see, nothing much is happening. The balloon just falls to the ground. Here the ball and the ceiling have balanced loads, nothing holds the ball to the ceiling, and nothing pushes it back.

The energy obtained on the basis of heat is called thermal energy (power). This work can also be done by water falling from huge man-made dams or waterfalls (hydropower). Wind power or solar heat can also be used to power generators that produce electricity, although these sources of energy are rarely used.

This is a perfectly balanced result of atomic charges. Our two elements have a lot of electrons, a balloon and a ceiling! Why brush off the ball? By rubbing the balloon, it is given an electric charge. We disturb the balance of electric charges that existed. The more we rub the ball, the more we tear apart the electrons.

Having lost their electrons, the balloon is dominated by positively charged protons. Therefore, it is positively charged and is out of balance with the ceiling as we will be able to observe it during this easy experiment. Why does the balloon stick to the ceiling? The balloon remains attached to the ceiling because the ceiling has a neutral charge with respect to the balloon, which under a given frictional load.

With the help of a giant magnet, the generator creates a stream of electrical charges, or electric current, which flows through copper wires. But in order for electricity to be transmitted over long distances - to residential buildings and industrial enterprises - it is necessary to increase the voltage, that is, the force that pushes the current. To do this, electricity passes through a device called a transformer. Travel-ready, but now too powerful and dangerous to use, electricity exits the power plant via huge cables that must be securely buried underground or strung high in the air using towers.

How magnets, ceiling and balloon attract! There is a dominant charge on the balloon and is opposite to the flow of electrical attraction. After a few minutes, you will see several hours if you rub your ball well, and the charges will start to balance.

Explanation of this simple science experiment with sweets

There is an exchange of electrons between the balloon and the ceiling, which is naturally balanced. When both elements restore their electrical balance, the ball falls. On a piece of paper, draw two large circles around the circle, and in the middle of each of these circles, draw a well-defined point.

When the electricity reaches its destination, it is passed through another transformer, which lowers its voltage so that it is suitable for normal use. After that, electricity is supplied to residential buildings and industrial enterprises through wires. The wires are connected to meters that record how much electricity is used in each home so that consumers can pay the cost of the electricity consumed to the manufacturing company.

Place a candy on each of these spots. Those candies in the center of the circles are the candies. By sticking to this candy, you can place 4 different shaped candies! These will be our protons, which are naturally positively charged! So we'll say it's true and it's all right!

We have just created the center of our atom. Now let's add some candy to the circle you drew earlier. These candies will be electrons, which are naturally negatively charged. You can add 4! That's all, our atom is complete, we will be able to observe live what happens during friction!

Wires laid through walls and floors bring electricity to every room of a house or apartment. These wires are connected through special devices called fuses or circuit breakers. Fuses interrupt the flow of electrical current (i.e., open the circuit) if, for some reason, the current increases to a dangerous level (which can cause overheating and fire). Household appliances that run on electricity - lighting, TV, toaster and others, can be connected to the current by pressing the switch or plugging the device into a socket.

When you rub your ball on your sweater, it wins or loses electrons, which has the effect of changing the charge of the atoms! If you remove one of the electronic candies present on the circle, the atom gets a positive charge because there are more positively charged protons.

Most of them are bigger! If you add electron convection to the circle, they will be in greater numbers, and the atom will have a negative charge! So much for this experiment on static electricity explained to the children! Feel free to share on social networks!

Electricity surrounds children everywhere: at home, on the street, in kindergarten, in toys and household appliances - it is difficult to remember the sphere of human life where they would do without electricity. Therefore, the interest of children in this topic is quite understandable. Although the story about the properties of electricity is not only a matter of curiosity, but also ... the safety of the baby!

At 2-3 years old, a little man begins a period when he is interested in everything. What is it, why, how it works, why it is, and nothing else, how it is used, what is useful or harmful - a million questions a day for dad and mom are guaranteed. Moreover, the area of \u200b\u200binterests of the “why” is extensive: he is concerned about both mundane topics (like that, or), and sublime ones (,). And questions about electricity are also natural. What is current, where does it come from and where does it disappear when we flip the switch? Why does the light bulb glow from electricity and the TV works? How does dad's or his work without a wire to an outlet? Why is the current so dangerous that parents forbid even approaching this outlet? The options are countless! Of course, you can dismiss them by saying that the child is still too young to understand this topic (from the point of view of science, electricity is such a complex concept that one can not talk about it until 12-14 years old). But this approach is wrong. And from the point of view of both education and safety. Let the kid not understand the physics of the process, but he is quite capable of knowing the essence of the electric current and treating it with due respect.

Electricity: bees or electrons?

So, let's start with a basic question: what is electricity? In communicating with a child of 2-3 years, several approaches are possible. First: gaming. You can tell the baby that, for example, small bees or ants live inside the wires, which are actually invisible to the human eye. And when the electrical appliance is turned off, they rest there, rest. But as soon as you connect it to the outlet (or press the switch if it is connected to the network), they begin to work: run or fly inside the wire back and forth without getting tired! And from such their movement, energy is generated that lights a light bulb or allows one or another device to work. Moreover, the number of such bees-ants in the wire can be different. The more of them and the more actively they move, the higher the current strength - which means that the larger mechanism they can start. Simply put, in order for a light bulb to glow in a flashlight, you need very few of these “helpers”, and to light up a house, you need to have a supply of electricity much, much more. And here it is important to emphasize: although such bees work for the benefit of people, they can be seriously offended if they are treated carelessly. Moreover, the matter will not be limited to resentment - they can also bite painfully painfully (and the more bees, the stronger the bite will be). And therefore, you can’t climb into the outlet or disassemble the electrical appliance, as well as touch the bare wires of the connected devices - the bees may not like that someone is trying to interfere with their work ...

If you don’t like this approach, you prefer to answer the child’s questions with all seriousness, then you can talk about the physical phenomenon of electricity only by adapting it for the little man. Explain that inside the metal wires there are microparticles - electrons. On the one hand, they are so small that it is impossible to see them even with a microscope, and on the other hand, there are a lot of them. In the normal state, they are in one place and do nothing. But when you turn on the device, the electrons begin to move at high speed inside the wires. This movement creates the energy of electricity. To make it clear to the baby how this is possible, you can compare it with water in pipes - it’s not for nothing that they say that current flows through the wires. Like drops of liquid in a tube, pushing each other, following one after another, running until the valve is closed, the electrons act exactly like this - only they have a switch instead of a valve. And from direct contact with electrons, unlike water, you do not get wet, but get an electric shock. This is a real blow: after all, there are a lot of electrons and they run at great speed. And therefore, if you stand in their way, they beat into the skin with great force, which, of course, is very painful. Therefore, if the device is plugged into an outlet or the wire is exposed (which is essentially equivalent to a pipe rupture when water flows out: and the more water, the stronger its pressure), you can not interfere with it. Let the electrons spend energy on a light bulb, and not on spending it offending the baby!

Demonstrate electricity with examples

Whatever approach you choose in the story about electricity, the following question is logical for children: why, when the device is turned on, bees or electrons begin to move in the wire, what makes them do it? In that case, you need to in general terms talk about the structure of the power grid, and it is advisable to do this with illustrative examples from the surrounding life or on photo and video materials. Tell that all-all the wires in the house converge into one cable that can accommodate the number of electrons / bees needed for housing. Then he goes outside and, leaning on poles, leads to a factory where these particles are produced - such a factory is called a power plant. You can talk about how they are produced (by burning coal, from a drive at a hydroelectric power station or windmills, from solar panels), if you wish, if the child shows interest in this. But usually in 2-3 years, the notion is enough that there is such a factory where “electric bees” or electrons are made. Although no one forbids you to conduct a small but visual experiment with your child. You will need the simplest dynamo: with a light bulb and a handle, from the rotation of which the light bulb glows. The kid will surely be delighted, seeing that he can produce electricity with his own hands! And as soon as he stops turning the handle, the light goes out immediately - very clearly and simply.

Experimental practice is generally extremely useful - especially in those matters where it is necessary to show that the current is dangerous. To do this, you will need a few batteries and a couple of light bulbs. First, explain that a battery is such a small supply of electricity: like canned food, in which electrons are stored to power appliances for a while. And then show how it works: installed it in a toy and a phone, they work. The charge of the bees / electrons has ended - the device has turned off: either new batteries are needed, or the old ones need to be charged, “filling” a batch of “helpers” from the outlet (emphasize that not everything can be charged, but only batteries called batteries). Now move on to experimentation. Take a 9 V battery (the one that is commonly called a crown) and invite the baby to touch both contacts at the same time with his tongue. A slight burning sensation that he feels is a manifestation of an electric shock - only weak, because there are very few bees or electrons in the battery. And in the socket there are an order of magnitude more of them, and the blow is ten times stronger and more painful. Of course, a considerable number of children will want to see this. Therefore, a different experiment is needed: with a pair of different light bulbs - at 4.5 V and 9 V. Connect the last one to the same battery - it glows. And then connect the one that is designed for a lower voltage - and it will burn out, and spectacularly: with a pop, a flash and glass blackened from the inside ... Explain that for such a small bulb there are too many electrons in the battery, or that the bees did not like what happened to them play to no avail and they ruined it. So in the socket for a person - there is a lot of current or the bees will be offended, and he can suffer greatly.

Learn to be careful with electricity!

Just remember: your goal is not to intimidate the child. If you go too far in this matter, there is a great risk that fear of electricity will settle in the soul of the baby. He will be terribly afraid of him, it will be difficult for him to use electrical appliances, he will avoid them and try not to turn them on himself. It is more correct not to scare, but to teach accuracy and a thrifty attitude to the current. Therefore, talk about the risks, but do not embellish all the details through measures.

To learn how to handle electricity, pay attention to these points:

you can not turn on any electrical appliances in the house without the permission of adults, they must know that the baby turns on and off the TV, or other large electrical appliance;

it is unacceptable to disassemble electrical appliances, even if they are unplugged or it seems to the baby that some part needs to be replaced - for example, a burnt out light bulb in;

you need to immediately inform adults about any problem with an electrical appliance: if it stops working, it starts to smell unpleasant, smoke or spark, if its case is broken or the wire is broken;

in no case should you wet an electrical appliance or wires - water, on the one hand, can disable it, and on the other hand, it is a good conductor for current, and therefore an electric shock can go through it;

electrical appliances must be handled carefully, not thrown or beaten, all wires must be twisted carefully, without kinks, and they must be pulled out of the socket not sharply and not by the wire, but smoothly and by the protective plug;

on the street you can’t approach broken wires hanging from a pole or sticking out of the ground, and even more so touch them, it’s forbidden to open the doors of transformer boxes and electrical panels;

show the child the generally accepted symbols of electricity, which should tell him that it is not worth approaching the objects and structures designated by them without the knowledge of adults under any circumstances.

And do not forget to the curiosity of the child. No matter how you explain safety rules to him, in any case, consciously or not, the baby will at least once try to climb into the outlet, break the wire and break the electrical appliance. Therefore, various devices, from plugs to special cable mounts, are vital!

Does your child already know about the benefits and dangers of electricity?

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Home / Electrical Engineering

10.05.2016 15:50

How to teach children about electricity? This question often arises among parents who want to satisfy the curiosity of their kids and not overload them with terms.

The other day I was interviewing for the position of editor of a children's magazine. So there they also gave the task - to figure out how to tell the kids about the electric current.

I decided to approach this task from different angles:

1. Poem.

3. Sketch spread (with prose and poem)

4. There was an idea to make another video, but, unfortunately, the equipment failed (the microphone failed. Now I present these masterpieces to the readers of Zaykin's site, maybe thanks to this they will tell their children about electric current.

The poem deliberately uses different styles of versification in order to show versatile approaches.

Electricity

What is current?
buddy,
It's like a river flow
But running along the wires -
Gives us light and joy.

Wires - conductors
Electric river.
Know that the current flows in a circle
in an electrical circuit.

It is worth breaking that chain -
Stop the current your way.

In wires microparticles,
They are called electrons
Just needs to recharge
And they run and run.

And from this we have
Everything works at the same time:

Light bulbs, fixtures,
In toys, all motors,
Mom's washer
And daddy's internet.
On the street - lanterns,
On TV - "Smeshariki" ...
Thank you electronics
So many years of service.

Ask who charges them.
I will support your interest.
Batteries help
Run a process in the chain.
Only in small appliances
Both in shape and weight.
For everything else
Build thermal power plants, nuclear power plants and hydroelectric power plants

The current is invisible, weightless
Light and joy - in every home
But everyone should not forget
You can't play with him at all!

It's very dangerous
For sons and daughters...

Electricity- this is such a thing, somewhat similar to the flow of a river. The current also flows in a powerful stream in one direction. Only the current flows through the wires and it is not fish that swim inside these wires, but microparticles (electrons), which come with the signs "+" and "-", they are also called positively charged and negatively charged. And the electric current is precisely the movement of these charged particles. Yes, it's all about charging. The source of charge for small devices and toys is batteries, which make the electrons wake up and run around, without a charge, the electrons will not want to move anywhere, but will randomly stagnate in place. But in order for light bulbs to shine, TVs, refrigerators and washing machines to work, batteries will not help, their charge power is too low. For these purposes, people have built huge power plants, it is from them that the electric current flows into our sockets and switches.
Electric current flows necessarily along two wires: from the source to the device along one wire, and back along the other wire. This forms a closed electrical circuit. Stopping this flow is very simple, for example, you need to press the switch button or unplug the device from the socket and the circuit will open. Electric current will stop flowing into the device, and the device will stop working until the next power-on.

Electricity is one form of energy. It is produced, for example, in batteries, but its main source is power plants, from where it enters our homes through thick wires or cables. Try to imagine how water flows in a river. Electricity moves through wires the same way. This is why electricity is called electric current. Electricity that is not moving anywhere is called static electricity.

A lightning flash is an instantaneous discharge of static electricity that has accumulated in thunderclouds. In such cases, electricity moves through the air from cloud to cloud or from cloud down to the ground.

Take a plastic comb and run it quickly and vigorously through your hair several times. Now hold the comb close to the pieces of paper and you will see that it will attract them like a magnet. When you brush your hair, static electricity builds up in your hairbrush. An object charged with static electricity can attract other objects.

Electric current moves through the wires only if they are connected in a closed ring - electrical circuit. Take, for example, a flashlight: the wires connecting the battery, light bulb and switch form a closed circuit. The electrical circuit in the figure above operates on the same principle. As long as there is current flowing through the circuit, the light bulb is on. If you open the circuit - say, disconnect the wire from the battery - the light will go out.

Materials that allow electric current to pass through are called conductors. From such materials - in particular, from copper, which conducts electricity well - make electrical wires. A live wire is dangerous to humans (our body is also a conductor!), so the wires are covered with a plastic braid. Plastic is an insulator, that is, a material that does not allow current to pass through.

ATTENTION! Electricity is dangerous to life. Electrical appliances and sockets should be handled with great care. Do not climb power line masts, or better yet, do not approach them at all!

How do you know which materials are conductors and which are insulators? Try to conduct one simple experiment. Everything you need for this is shown in the picture above. First you will need to assemble an electrical circuit - such as I described above.

Disconnect one of the wires. As a result, the circuit will open and the light will go out. Now take a paperclip and lay it down to repair the chain. Is the light on or not?

Try replacing the paperclip with something else, such as a fork or an eraser. If the bulb lights up, then it is a conductor, if it does not light up, it is an insulator.

Electricity is generated in power plants. From there, it enters cities and villages through power lines - wires that are stretched on high masts. Electricity is supplied directly to the houses through wires laid underground.

These toy electric cars can be controlled by varying the amount of current flowing through the metal race track. Many electrically powered machines have complex electronic circuits that control their operation.

This toy train is equipped with an electric motor. The current, passing through the metal rails, enters the motor. Under the influence of current, the motor drives the wheels. When the electricity is turned off, the train stops.

This is interesting.
On the roofs of tall buildings, lightning rods are often installed - metal rods connected to the ground. Metals are good conductors. If lightning strikes a building, the metal rod attracts electricity and the discharge goes into the ground without harming anyone.

Greetings, dear readers! In this article, I want to tell you about the hit of our DIY homemade toys. This toy, made a couple of years ago, is so much liked by my eldest and youngest son that I simply cannot help but write about it. This toy is called an electric stand. I made it primarily in order to teach the child how to use switches, and then the idea came up to talk about electricity for children based on this toy. After all, the best way to tell children about something is to do something with them and show them how it works.

In my article, I will talk about this:

My electric stand is probably one of the simplest that you can make yourself. I did not set myself the task of doing something complicated and showing the wonders of owning a soldering iron. At the time when I was making the first version of the stand, we lived in Moscow in a rented house, there was little free time and I wanted to quickly make an interesting educational toy for my child hands. I wanted to make a toy from switches, a fan, light bulbs. I made the first version of this toy before and. I found stands on the Internet, but oddly enough, what was made of switches and sockets DID NOT WORK, i.e. it was switches, sockets and regulators screwed to the board and that's it. No batteries, bulbs, wires. I imagined that my son would flip the switches, and that's it, the learning process will be completed and this stand will gather dust in the corner. Therefore, I decided to take the issue more seriously and made everything workable. I made the first version of the stand based on a salad bowl. It worked for me for a long time, until my son began to test it for strength and its body began to crack. Then I finalized the body and this is the stand I got:

The simplest electric stand from a cooler, three switches and LEDs

Electric stand for children - details and manufacturing process

For the manufacture of the stand in my version, you will need the following materials:

1. Plastic bucket

2. Computer fan from the processor

3. Two latching switches, one push button switch

4. Four LEDs

5. Wires, a piece of flexible wire about 0.5 m long and 1-2 mm in diameter.

6. Battery "krone"

7. 1.5 liter plastic bottle

Of the tools you will need - a drill, a soldering iron, an awl, pliers, side cutters, a clerical knife.

First, mark out the mounts for the fan (I placed it at the top in the center). Then we fix the fan (you can use screws, you can, like mine with a flexible wire). Along the edges we make holes for LEDs and switches. My son actively participated in the manufacturing process, and at that time I told him why each detail was needed and what would need to be done to make it work.

Son marking the holes for the cooler

I placed the LEDs along the edges on the top of the bucket. I drilled holes under them, and then glued them from the inside so that they would not fall out.

By the way, I found interesting LEDs in the radio parts store, which flash in different colors when the power is connected - it turns out quite beautifully. I'm wondering, is there a microcircuit inside and three built-in LEDs (to get three colors), or is it somehow done differently?

The most interesting thing for my child was, of course, sorting out our old toy. The cracks in it were already so large that it was impossible to restore, and the view was already lost. It's good that all the electrical part remained normal, so I just transferred the parts to the new case.

Dismantling an old toy - that's interesting

After the LEDs, I fixed the switches and on the reverse side, soldered the wires. I had switches with built-in bulbs and I made it so that when you turn on the light on the switch itself, it also lights up.

To turn on the cooler, I used a push-button switch, because children rarely turn off the toy, and so - I pressed the button it works, let it go - it turned off
I used a rechargeable battery for the same reasons (children quickly discharge it), it turned out to be cheaper than buying a new one every time. To connect the krone battery, I used a special adapter that is attached to the battery and makes it easy to disconnect and connect the battery.

Electric stand connection diagram

For the operation of the power stand, the simplest connection scheme is used - after all, we have three functions:

Turn on the button - the light on the button lights up and the cooler turns on
We click one switch - the LEDs light up and start flashing
We click the second switch - the light on the switch lights up

In the diagram: switch VK1 is a switch for LEDs, VK 2 is a button that turns on the cooler, and VK 3 is a switch on which the light turns on when turned on. L1 and L2 are light bulbs built into switches VK1 and VK2, respectively.

How to play with the power stand?

After connecting and checking the operation of the electrical part, I fixed the neck of the plastic bottle on the fan, expanding part up. In order not to attach additional wires, I picked up such a size that it fits tightly on the cooler and does not fall off. What is it for? Here is the highlight of the game - the child really likes to throw tennis balls or other small toys on top of the cooler and as a result they either start spinning or bouncing merrily))))) Turning the LEDs on and off is the dimensions of our power stand, which has become an amazing machine. In general, you can watch the process on the video:

How to talk about electricity for children using an electric stand as an example?

The most important thing, of course, is to involve children in the manufacture of the electric stand. When we made this toy, I showed my son a battery, connected a light bulb to it with wires, gave him the opportunity to connect it himself, so that his son could see at what moment the light turns on and that if the circuit is opened, it immediately goes out.
I talked about electricity like this:

“There are many particles in a battery, invisible, but each of them has a power. And the more particles, the stronger they are together. They are called electrons. There are a lot of them in the battery and they really want to get out. These electrons can only run from one terminal of the battery to another (showed the terminals on the battery).

Electrons can easily run only along wires, but when a light bulb or a motor meets them on the way, it is more difficult for them to run and in order to run they begin to give up part of their strength. As a result, we see the light from the bulb and the motor is spinning. The longer we have a light bulb on, or a battery-powered fan spins, the more electronics will lose power and the battery will run out.

And if the electrons have nowhere to run (we remove the wires from the battery), then they do not run anywhere and do not lose their strength. In order to start the electrons back into the battery, we charge it and then it will be possible to reconnect the light bulb and the fan.”

This is the explanation I used to explain such seemingly simple and at the same time things that are not always clear to us, adults. After all, as far as I remember, science has not yet decided - “electrons run from plus to minus, or from minus to plus?”

And how did you, dear readers, explain to children about electricity? Share in your comments, because this is a very necessary topic and interesting for children.

In everyday life, we often come across such a concept as "electricity". What is electricity, have people always known about it?

It is almost impossible to imagine our modern life without electricity. Tell me, how can you do without lighting and heat, without an electric motor and telephone, without a computer and TV? Electricity has penetrated so deeply into our lives that sometimes we don’t even think what kind of magician helps us in our work.

This wizard is electricity. What is the essence of electricity? The essence of electricity is that the flow of charged particles moves along a conductor (a conductor is a substance capable of conducting electric current) in a closed circuit from a current source to a consumer. Moving, the flow of particles perform a certain work.

This phenomenon is called electricity". The strength of an electric current can be measured. The unit of measurement of current strength - Ampere, got its name in honor of the French scientist who was the first to investigate the properties of current. The name of the physicist is Andre Ampère.

The discovery of electric current and other innovations associated with it can be attributed to the period: the end of the nineteenth - the beginning of the twentieth century. But people observed the first electrical phenomena as early as the fifth century BC. They noticed that a piece of amber worn with fur or wool attracts light bodies, for example, dust particles. The ancient Greeks even learned to use this phenomenon to remove dust from expensive clothes. They also noticed that if dry hair was combed with an amber comb, they stood up, pushing away from each other.

Let's go back to the definition of electric current. Current is the directed movement of charged particles. If we are dealing with a metal, then charged particles are electrons. The Greek word for amber is electron.

Thus, we understand that the well-known concept of "electricity" has ancient roots.

Electricity is our friend. It helps us in everything. In the morning we turn on the light, the electric kettle. We put the food in the microwave to heat up. We use the elevator. We ride the tram, we talk on the cell phone. We work in industrial enterprises, in banks and hospitals, in the fields and in workshops, we study at a school where it is warm and light. And electricity works everywhere.

Like many things in our life, electricity has not only a positive, but also a negative side. An electric current, like an invisible wizard, cannot be seen, smelled. It is possible to determine the presence or absence of current only using instruments, measuring equipment. The first case of fatal electric shock was described in 1862. The tragedy occurred when a person accidentally came into contact with live parts. In the future, there were many cases of electric shock.

Electricity! Attention electricity!

This story about electricity is for children. But, in itself, electricity is not a childish concept. Therefore, in this story, I would like to turn to moms and dads, grandparents.

Dear adults! When talking about electricity to children, do not forget to emphasize that the current is invisible, and therefore especially insidious. What not to do for adults and children? Do not touch with your hands, do not come close to wires and electrical complexes. Near power lines, substations, do not stop for rest, do not make fires, do not launch flying toys. A wire lying on the ground can be fraught with mortal danger. Electrical outlets, if there is a small child in the house, is an object of special control.

The main requirement for adults is not only to follow the safety rules themselves, but also to constantly inform children about how insidious electric current can be.

Conclusion

Physicists "gave access" to humanity to electricity. For the sake of the future, scientists went to hardships, spent fortunes to make great discoveries and give the results of their labors to people.

Let us treat the works of physicists and electricity with care, and let us remember the danger that it potentially carries.

You can watch the fable about electricity

Electricity: bees or electrons?

Demonstrate electricity with examples

Whatever approach you choose in the story about electricity, the following question is logical for children: why, when the device is turned on, bees or electrons begin to move in the wire, what makes them do it? In this case, it is necessary to talk in general terms about the structure of the power grid, and it is advisable to do this with illustrative examples from the surrounding life or on photo and video materials. Tell that all-all the wires in the house converge into one cable that can accommodate the number of electrons / bees needed for housing. Then he goes outside and, leaning on poles, leads to a factory where these particles are produced - such a factory is called a power plant. You can talk about how they are produced (by burning coal, from a drive at a hydroelectric power station or windmills, from solar panels), if you wish, if the child shows interest in this. But usually in 2-3 years, the notion is enough that there is such a factory where “electric bees” or electrons are made. Although no one forbids you to conduct a small but visual experiment with your child. You will need the simplest dynamo: with a light bulb and a handle, from the rotation of which the light bulb glows. The kid will surely be delighted, seeing that he can produce electricity with his own hands! And as soon as he stops turning the handle, the light goes out immediately - very clearly and simply.

Learn to be careful with electricity!

To learn how to handle electricity, pay attention to these points:

you can not turn on any electrical appliances in the house without the permission of adults, they must know that the baby turns on and off the TV, or other large electrical appliance;

it is unacceptable to disassemble electrical appliances, even if they are unplugged or it seems to the baby that some part needs to be replaced - for example, a burnt out light bulb;

you need to immediately inform adults about any problem with an electrical appliance: if it stops working, it starts to smell unpleasant, smoke or spark, if its case is broken or the wire is broken;

The physics of electricity is something that each of us has to face. In the article we will consider the basic concepts associated with it.

What is electricity? For an uninitiated person, it is associated with a flash of lightning or with the energy that feeds the TV and washing machine. He knows that electric trains use electrical energy. What else can he say? Power lines remind him of our dependence on electricity. Someone can give a few other examples.

However, many other, not so obvious, but everyday phenomena are connected with electricity. Physics introduces us to all of them. We begin to study electricity (tasks, definitions and formulas) at school. And we learn a lot of interesting things. It turns out that a beating heart, a running athlete, a sleeping baby, and a swimming fish all generate electrical energy.

Electrons and protons

Let's define the basic concepts. From the point of view of a scientist, the physics of electricity is associated with the movement of electrons and other charged particles in various substances. Therefore, the scientific understanding of the nature of the phenomenon of interest to us depends on the level of knowledge about atoms and their constituent subatomic particles. The tiny electron is the key to this understanding. The atoms of any substance contain one or more electrons that move in various orbits around the nucleus, just as the planets revolve around the sun. Usually the number of electrons in an atom is equal to the number of protons in the nucleus. However, protons, being much heavier than electrons, can be considered as if fixed in the center of the atom. This extremely simplified model of the atom is quite enough to explain the basics of such a phenomenon as the physics of electricity.

What else do you need to know? Electrons and protons have the same electrical charge (but different sign), so they are attracted to each other. The charge of a proton is positive and that of an electron is negative. An atom that has more or less electrons than usual is called an ion. If there are not enough of them in an atom, then it is called a positive ion. If it contains an excess of them, then it is called a negative ion.

When an electron leaves an atom, it acquires some positive charge. An electron, deprived of its opposite - a proton, either moves to another atom, or returns to the previous one.

Why do electrons leave atoms?

This is due to several reasons. The most general is that under the influence of a pulse of light or some external electron, an electron moving in an atom can be knocked out of its orbit. Heat makes the atoms vibrate faster. This means that electrons can fly out of their atom. In chemical reactions, they also move from atom to atom.

Muscles provide a good example of the relationship between chemical and electrical activity. Their fibers contract when exposed to an electrical signal coming from nervous system. Electric current stimulates chemical reactions. They lead to muscle contraction. External electrical signals are often used to artificially stimulate muscle activity.

Conductivity

In some substances, electrons under the action of an external electric field move more freely than in others. Such substances are said to have good conductivity. They are called conductors. These include most metals, heated gases, and some liquids. Air, rubber, oil, polyethylene and glass are poor conductors of electricity. They are called dielectrics and are used to insulate good conductors. Ideal insulators (absolutely non-conductive) do not exist. Under certain conditions, electrons can be removed from any atom. However, these conditions are usually so difficult to meet that, from a practical point of view, such substances can be considered non-conductive.

Getting acquainted with such a science as physics (section "Electricity"), we learn that there is a special group of substances. These are semiconductors. They behave partly as dielectrics and partly as conductors. These include, in particular: germanium, silicon, copper oxide. Due to its properties, the semiconductor finds many applications. For example, it can serve as an electric valve: like a bicycle tire valve, it allows charges to move in only one direction. Such devices are called rectifiers. They are used in miniature radios and large power plants to convert AC to DC.

Heat is a chaotic form of movement of molecules or atoms, and temperature is a measure of the intensity of this movement (in most metals, with decreasing temperature, the movement of electrons becomes freer). This means that the resistance to the free movement of electrons decreases with decreasing temperature. In other words, the conductivity of metals increases.

Superconductivity

In some substances at very low temperatures the resistance to the flow of electrons disappears completely, and the electrons, having begun to move, continue it indefinitely. This phenomenon is called superconductivity. At a temperature of several degrees above absolute zero (-273 ° C), it is observed in metals such as tin, lead, aluminum and niobium.

Van de Graaff generators

The school curriculum includes various experiments with electricity. There are many types of generators, one of which we would like to talk about in more detail. The Van de Graaff generator is used to produce ultra-high voltages. If an object containing an excess of positive ions is placed inside a container, then electrons will appear on the inner surface of the latter, and the same number of positive ions will appear on the outer surface. If we now touch the inner surface with a charged object, then all the free electrons will pass to it. On the outside, positive charges will remain.

In a Van de Graaff generator, positive ions from a source are applied to a conveyor belt that runs inside a metal sphere. The tape is connected to the inner surface of the sphere with the help of a conductor in the form of a comb. The electrons flow down from the inner surface of the sphere. Positive ions appear on its outer side. The effect can be enhanced by using two generators.

Electricity

The school physics course also includes such a concept as electric current. What is it? Electric current is due to the movement of electric charges. When an electric lamp connected to a battery is turned on, current flows through a wire from one pole of the battery to the lamp, then through its hair, causing it to glow, and back through the second wire to the other pole of the battery. If the switch is turned, the circuit will open - the current will stop flowing, and the lamp will go out.

Electron movement

Current in most cases is an ordered movement of electrons in a metal that serves as a conductor. In all conductors and some other substances there is always some random movement going on, even if there is no current flowing. Electrons in matter can be relatively free or strongly bound. Good conductors have free electrons that can move around. But in poor conductors, or insulators, most of these particles are strongly enough connected with atoms, which prevents their movement.

Sometimes, naturally or artificially, a movement of electrons in a certain direction is created in a conductor. This flow is called electric current. It is measured in amperes (A). Ions (in gases or solutions) and “holes” (lack of electrons in some types of semiconductors) can also serve as current carriers. The latter behave like positively charged electric current carriers. Some force is needed to make electrons move in one direction or another. In nature its sources can be: exposure to sunlight, magnetic effects and chemical reactions.Some of them are used to generate electric current.Usually for this purpose are: a generator using magnetic effects, and an element (battery) whose action is caused chemical reactions. Both devices, by creating an electromotive force (EMF), cause the electrons to move in the same direction along the circuit. The EMF value is measured in volts (V). These are the basic units of measurement for electricity.

The magnitude of the EMF and the strength of the current are interconnected, like pressure and flow in a liquid. Water pipes are always filled with water at a certain pressure, but water only starts flowing when the tap is turned on.

Similarly, an electrical circuit can be connected to a source of emf, but current will not flow until a path has been created for the electrons to move. It can be, say, an electric lamp or a vacuum cleaner, the switch here plays the role of a tap that “releases” the current.

Relationship between current and voltage

As the voltage in the circuit increases, so does the current. Studying a physics course, we learn that electrical circuits consist of several different sections: usually a switch, conductors and a device that consumes electricity. All of them, connected together, create a resistance to electric current, which (assuming a constant temperature) for these components does not change with time, but is different for each of them. Therefore, if the same voltage is applied to a light bulb and to an iron, then the flow of electrons in each of the devices will be different, since their resistances are different. Consequently, the strength of the current flowing through a certain section of the circuit is determined not only by voltage, but also by the resistance of conductors and devices.

Ohm's law

The magnitude of electrical resistance is measured in ohms (Ohm) in a science such as physics. Electricity (formulas, definitions, experiments) is a vast topic. We will not derive complex formulas. For the first acquaintance with the topic, what has been said above is enough. However, one formula is still worth deriving. She is quite uncomplicated. For any conductor or system of conductors and devices, the relationship between voltage, current and resistance is given by the formula: voltage = current x resistance. This is the mathematical expression of Ohm's law, named after George Ohm (1787-1854), who was the first to establish the relationship of these three parameters.

The physics of electricity is a very interesting branch of science. We have considered only the basic concepts associated with it. You learned what electricity is, how it is formed. We hope you find this information useful.

Electricity for dummies. School for electrician

We offer a small material on the topic: "Electricity for beginners." It will give an initial idea of the terms and phenomena associated with the movement of electrons in metals.

Term Features

Electricity is the energy of small charged particles moving in conductors in a certain direction.

With direct current, there is no change in its magnitude, as well as the direction of movement for a certain period of time. If a galvanic cell (battery) is chosen as the current source, then the charge moves in an orderly manner: from the negative pole to the positive end. The process continues until it completely disappears.

Alternating current periodically changes the magnitude, as well as the direction of movement.

AC transmission scheme

Let's try to understand what a phase is in electricity. Everyone has heard this word, but not everyone understands its true meaning. We will not go into details and details, we will choose only the material that the home master needs. A three-phase network is a method of transmitting electric current, in which current flows through three different wires, and it returns through one. For example, there are two wires in an electrical circuit.

On the first wire to the consumer, for example, to the kettle, there is a current. The second wire is used for its return. When such a circuit is opened, there will be no passage of an electric charge inside the conductor. This diagram describes a single-phase circuit. What is a phase in electricity? A phase is a wire through which an electric current flows. Zero is the wire through which the return is made. In a three-phase circuit, there are three phase wires at once.

The electrical panel in the apartment is necessary for the distribution of electric current to all rooms. Three-phase networks are considered economically feasible, since they do not require two neutral wires. When approaching the consumer, the current is divided into three phases, each with zero. The earthing switch, which is used in a single-phase network, does not carry a working load. He is a fuse.

For example, if a short circuit occurs, there is a threat of electric shock, fire. To prevent such a situation, the current value should not exceed a safe level, the excess goes to the ground.

The manual "School for an electrician" will help novice craftsmen to cope with some breakdowns of household appliances. For example, if there are problems with the operation of the electric motor of the washing machine, the current will fall on the outer metal case.

In the absence of grounding, the charge will be distributed throughout the machine. When you touch it with your hands, a person will act as a ground electrode, having received an electric shock. If there is a ground wire, this situation will not occur.

Features of electrical engineering

The manual "Electricity for Dummies" is popular with those who are far from physics, but plan to use this science for practical purposes.

The beginning of the nineteenth century is considered the date of the appearance of electrical engineering. It was at this time that the first current source was created. The discoveries made in the field of magnetism and electricity have managed to enrich science with new concepts and facts of great practical importance.

The "School for an Electrician" manual assumes familiarity with the basic terms related to electricity.

Many collections of physics contain complex electrical circuits, as well as a variety of obscure terms. In order for beginners to understand all the intricacies of this section of physics, a special manual “Electricity for Dummies” was developed. An excursion into the world of the electron must begin with a consideration of theoretical laws and concepts. Illustrative examples, historical facts used in the book "Electricity for Dummies" will help novice electricians learn knowledge. To check progress, you can use tasks, tests, exercises related to electricity.

If you understand that you do not have enough theoretical knowledge to independently cope with the connection of electrical wiring, refer to the manuals for "dummies".

Safety and practice

First you need to carefully study the section on safety. In this case, during work related to electricity, there will be no emergencies hazardous to health.

In order to put into practice the theoretical knowledge gained after self-study of the basics of electrical engineering, you can start with old household appliances. Before starting repairs, be sure to read the instructions that came with the device. Do not forget that electricity is not to be trifled with.

Electric current is associated with the movement of electrons in conductors. If a substance is not capable of conducting current, it is called a dielectric (insulator).

For the movement of free electrons from one pole to another, a certain potential difference must exist between them.

The intensity of the current passing through a conductor is related to the number of electrons passing through the cross section of the conductor.

The current flow rate is affected by the material, length, cross-sectional area of the conductor. As the length of the wire increases, its resistance increases.

Conclusion

Electricity is an important and complex branch of physics. The manual "Electricity for Dummies" considers the main quantities that characterize the efficiency of electric motors. Voltage units are volts, current is measured in amperes.

Any source of electrical energy has a certain power. It refers to the amount of electricity generated by the device in a certain period of time. Energy consumers (refrigerators, washing machines, kettles, irons) also have power, consuming electricity during operation. If you wish, you can carry out mathematical calculations, determine the approximate fee for each household appliance.

Electricity

Classical electrodynamics

Electricity Magnetism

Electrostatics Magnetostatics Electrodynamics Electric circuit Covariant formulation Famous scientists

Classification

If charged particles move inside macroscopic bodies relative to a particular medium, then such a current is called electric conduction current. If macroscopic charged bodies are moving (for example, charged raindrops), then this current is called convection.

There are direct and alternating electric currents, as well as all kinds of alternating current. In such terms, the word "electric" is often omitted.

D.C - current, the direction and magnitude of which do not change with time.

Alternating current is an electric current that changes with time. Alternating current is any current that is not direct.

Periodic current - electric current, the instantaneous values of which are repeated at regular intervals in an unchanged sequence.

Sinusoidal current - periodic electric current, which is a sinusoidal function of time. Among the alternating currents, the main one is the current, the value of which varies according to a sinusoidal law. In this case, the potential of each end of the conductor changes with respect to the potential of the other end of the conductor alternately from positive to negative and vice versa, while passing through all intermediate potentials (including the zero potential). As a result, a current arises that continuously changes direction: when moving in one direction, it increases, reaching a maximum, called the amplitude value, then decreases, at some point becomes zero, then increases again, but in the other direction and also reaches the maximum value , falls off to then pass through zero again, after which the cycle of all changes resumes.

Quasi-stationary current - “a relatively slowly changing alternating current, for the instantaneous values of which the laws of direct currents are satisfied with sufficient accuracy” (TSB). These laws are Ohm's law, Kirchhoff's rules and others. Quasi-stationary current, as well as direct current, has the same current strength in all sections of an unbranched circuit. When calculating quasi-stationary current circuits due to the emerging e. d.s. capacitance and inductance inductions are taken into account as lumped parameters. Quasi-stationary are ordinary industrial currents, except for currents in long-distance transmission lines, in which the condition of quasi-stationarity along the line is not satisfied.

high frequency current - alternating current, (starting from a frequency of approximately tens of kHz), for which such phenomena as the radiation of electromagnetic waves and the skin effect become significant. In addition, if the wavelength of the AC radiation becomes comparable to the dimensions of the elements of the electrical circuit, then the condition of quasi-stationarity is violated, which requires special approaches to the calculation and design of such circuits. (see long line).

Ripple current is a periodic electric current, the average value of which over the period is different from zero.

Unidirectional current is an electric current that does not change its direction.

Eddy currents

Main article: Eddy currents

Eddy currents (Foucault currents) are “closed electric currents in a massive conductor that occur when the magnetic flux penetrating it changes,” therefore eddy currents are induction currents. The faster the magnetic flux changes, the stronger the eddy currents. Eddy currents do not flow along certain paths in the wires, but, closing in the conductor, form vortex-like contours.

The existence of eddy currents leads to the skin effect, that is, to the fact that the alternating electric current and magnetic flux propagate mainly in the surface layer of the conductor. Eddy current heating of conductors leads to energy losses, especially in the cores of AC coils. To reduce energy losses due to eddy currents, the alternating current magnetic circuits are divided into separate plates, isolated from each other and located perpendicular to the direction of eddy currents, which limits the possible contours of their paths and greatly reduces the magnitude of these currents. At very high frequencies, instead of ferromagnets, magnetodielectrics are used for magnetic circuits, in which, due to the very high resistance, eddy currents practically do not occur.

Characteristics

It is historically accepted that current direction coincides with the direction of movement of positive charges in the conductor. In this case, if the only current carriers are negatively charged particles (for example, electrons in a metal), then the direction of the current is opposite to the direction of movement of charged particles.

Drift velocity of electrons

The speed (drift) of the directional movement of particles in conductors caused by an external field depends on the material of the conductor, the mass and charge of the particles, the ambient temperature, the applied potential difference and is much less than the speed of light. For 1 second, the electrons in the conductor move due to the ordered movement by less than 0.1 mm - 20 times slower than the speed of the snail [ source not specified 257 days]. Despite this, the propagation speed of the actual electric current is equal to the speed of light (the propagation speed of the electromagnetic wave front). That is, the place where the electrons change their speed of movement after a change in voltage moves with the speed of propagation of electromagnetic oscillations.

Strength and current density

Main article: Current strength

Electric current has quantitative characteristics: scalar - current strength, and vector - current density.

Current strength- a physical quantity equal to the ratio of the amount of charge Δ Q (\displaystyle \Delta Q) that has passed for some time Δ t (\displaystyle \Delta t) through the cross section of the conductor, to the value of this time interval.

I = ∆ Q ∆ t . (\displaystyle I=(\frac (\Delta Q)(\Delta t)).)

Current in international system units (SI) is measured in amperes (Russian designation: A; international: A).

According to Ohm's law, the current I (\displaystyle I) in a circuit section is directly proportional to the voltage U (\displaystyle U) applied to this section of the circuit, and inversely proportional to its resistance R (\displaystyle R) :

I = U R . (\displaystyle I=(\frac (U)(R)).)

If the electric current is not constant in the circuit section, then the voltage and current strength are constantly changing, while for ordinary alternating current the average values of voltage and current strength are equal to zero. However, the average power of the heat released in this case is not equal to zero. Therefore, the following terms are used:

instantaneous voltage and current, that is, acting at a given moment in time.
peak voltage and current, that is, the maximum absolute values
effective (effective) voltage and current strength are determined by the thermal effect of the current, that is, they have the same values \u200b\u200bthat they have for direct current with the same thermal effect.

Current density is a vector, the absolute value of which is equal to the ratio of the current flowing through a certain section of the conductor, perpendicular to the direction of the current, to the area of this section, and the direction of the vector coincides with the direction of movement of positive charges that form the current.

According to Ohm's law in differential form, the current density in the medium j → (\displaystyle (\vec (j))) is proportional to the electric field strength E → (\displaystyle (\vec (E))) and the conductivity of the medium σ (\displaystyle \ \sigma ) :

J → = σ E → . (\displaystyle (\vec (j))=\sigma (\vec (E)).)

Power

Main article: Joule-Lenz law

In the presence of current in the conductor, work is done against the forces of resistance. The electrical resistance of any conductor consists of two components:

active resistance - resistance to heat generation;
reactance - "resistance due to the transfer of energy to an electric or magnetic field (and vice versa)" (TSB).

Generally, most of the work done by an electric current is released as heat. The power of heat loss is a value equal to the amount of heat released per unit time. According to the Joule-Lenz law, the power of heat loss in a conductor is proportional to the strength of the flowing current and the applied voltage:

P = I U = I 2 R = U 2 R (\displaystyle P=IU=I^(2)R=(\frac (U^(2))(R)))

Power is measured in watts.

In a continuous medium, the volumetric power loss p (\displaystyle p) is determined by the scalar product of the current density vector j → (\displaystyle (\vec (j))) and the electric field strength vector E → (\displaystyle (\vec (E))) in given point:

P = (j → E →) = σ E 2 = j 2 σ (\displaystyle p=\left((\vec (j))(\vec (E))\right)=\sigma E^(2)= (\frac (j^(2))(\sigma )))

Volumetric power is measured in watts per cubic meter.

Radiation resistance is caused by the formation of electromagnetic waves around the conductor. This resistance is in complex dependence on the shape and dimensions of the conductor, on the wavelength of the emitted wave. For a single rectilinear conductor, in which the current is of the same direction and strength everywhere, and the length of which L is much less than the length of the electromagnetic wave radiated by it λ (\displaystyle \lambda ) , the dependence of resistance on the wavelength and conductor is relatively simple:

R = 3200 (L λ) (\displaystyle R=3200\left((\frac (L)(\lambda ))\right))

The most used electric current with a standard frequency of 50 Hz corresponds to a wave with a length of about 6 thousand kilometers, which is why the radiation power is usually negligibly small compared to the heat loss power. However, as the frequency of the current increases, the length of the emitted wave decreases, and the radiation power increases accordingly. A conductor capable of radiating appreciable energy is called an antenna.

Frequency

Bias current

Main article: Displacement current (electrodynamics)

Sometimes, for convenience, the concept of displacement current is introduced. In Maxwell's equations, the displacement current is present on an equal footing with the current caused by the movement of charges. The intensity of the magnetic field depends on the total electric current, which is equal to the sum of the conduction current and the displacement current. By definition, the displacement current density j D → (\displaystyle (\vec (j_(D)))) is a vector quantity proportional to the rate of change of the electric field E → (\displaystyle (\vec (E))) in time:

J D → = ∂ E → ∂ t (\displaystyle (\vec (j_(D)))=(\frac (\partial (\vec (E)))(\partial t)))

The fact is that when the electric field changes, as well as when the current flows, a magnetic field is generated, which makes these two processes similar to each other. In addition, a change in the electric field is usually accompanied by energy transfer. For example, when charging and discharging a capacitor, despite the fact that there is no movement of charged particles between its plates, they speak of a displacement current flowing through it, carrying some energy and closing the electrical circuit in a peculiar way. The bias current I D (\displaystyle I_(D)) in a capacitor is given by:

I D = d Q d t = − C d U d t (\displaystyle I_(D)=(\frac ((\rm (d))Q)((\rm (d))t))=-C(\frac ( (\rm (d))U)((\rm (d))t))) ,

where Q (\displaystyle Q) is the charge on the capacitor plates, U (\displaystyle U) is the potential difference between the plates, C (\displaystyle C) is the capacitance of the capacitor.

Displacement current is not an electric current, because it is not related to the movement of an electric charge.

Main types of conductors

Unlike dielectrics, conductors contain free carriers of uncompensated charges, which, under the action of a force, usually a difference in electrical potentials, set in motion and create an electric current. The current-voltage characteristic (current versus voltage) is the most important characteristic conductor. For metallic conductors and electrolytes, it has the simplest form: the current strength is directly proportional to the voltage (Ohm's law).

Metals - here the current carriers are conduction electrons, which are usually considered as an electron gas, clearly showing the quantum properties of a degenerate gas.

Plasma is an ionized gas. Electric charge is carried by ions (positive and negative) and free electrons, which are formed under the influence of radiation (ultraviolet, X-ray and others) and (or) heating.

Electrolytes - "liquid or solid substances and systems in which ions are present in any noticeable concentration, causing the passage of an electric current." Ions are formed in the process of electrolytic dissociation. When heated, the resistance of electrolytes decreases due to an increase in the number of molecules decomposed into ions. As a result of the passage of current through the electrolyte, the ions approach the electrodes and are neutralized, settling on them. Faraday's laws of electrolysis determine the mass of the substance released on the electrodes.

There is also an electric current of electrons in a vacuum, which is used in cathode ray devices.

Electric currents in nature

Intracloud lightning over Toulouse, France. 2006

Atmospheric electricity is electricity that is contained in the air. For the first time, Benjamin Franklin showed the presence of electricity in the air and explained the cause of thunder and lightning. Subsequently, it was established that electricity accumulates in the condensation of vapors in the upper atmosphere, and the following laws were indicated, which atmospheric electricity follows:

with a clear sky, as well as with a cloudy sky, the electricity of the atmosphere is always positive, if at some distance from the observation point it does not rain, hail or snow;
the electricity voltage of the clouds becomes strong enough to release it from environment only when cloud vapors condense into raindrops, as evidenced by the fact that there are no lightning discharges without rain, snow or hail at the place of observation, excluding the return stroke of lightning;
atmospheric electricity increases with increasing humidity and reaches a maximum when rain, hail and snow fall;
the place where it rains is a reservoir of positive electricity, surrounded by a belt of negative electricity, which, in turn, is enclosed in a belt of positive. At the boundaries of these belts, the stress is zero. The movement of ions under the action of electric field forces forms a vertical conduction current in the atmosphere with an average density equal to about (2÷3)·10−12 A/m².

The total current flowing to the entire surface of the Earth is approximately 1800 A.

Lightning is a natural sparking electrical discharge. The electrical nature of the auroras was established. St. Elmo's fires are a natural corona electrical discharge.

Biocurrents - the movement of ions and electrons plays a very significant role in all life processes. The biopotential created in this case exists both at the intracellular level and in individual parts of the body and organs. The transmission of nerve impulses occurs with the help of electrochemical signals. Some animals (electric rays, electric eel) are able to accumulate a potential of several hundred volts and use this for self-defense.

Application

When studying the electric current, many of its properties were discovered, which allowed him to find practical use in various areas of human activity, and even create new areas that would not be possible without the existence of electric current. After the electric current found practical application, and for the reason that the electric current can be obtained in various ways, a new concept arose in the industrial sphere - the electric power industry.

Electric current is used as a carrier of signals of varying complexity and types in different areas (telephone, radio, control panel, door lock button, and so on).

In some cases, unwanted electric currents appear, such as stray currents or short circuit current.

The use of electric current as a carrier of energy

obtaining mechanical energy in various electric motors,
obtaining thermal energy in heating devices, electric furnaces, during electric welding,
obtaining light energy in lighting and signaling devices,
excitation of electromagnetic oscillations of high frequency, ultrahigh frequency and radio waves,
receiving sound,
obtaining various substances by electrolysis, charging electric batteries. This is where electromagnetic energy is converted into chemical energy.
creating a magnetic field (in electromagnets).

The use of electric current in medicine

diagnostics - the biocurrents of healthy and diseased organs are different, while it is possible to determine the disease, its causes and prescribe treatment. The branch of physiology that studies electrical phenomena in the body is called electrophysiology.
- Electroencephalography is a method for studying the functional state of the brain.
- Electrocardiography is a technique for recording and studying electric fields during the work of the heart.
- Electrogastrography is a method for studying the motor activity of the stomach.
- Electromyography is a method for studying bioelectric potentials that occur in skeletal muscles.
Treatment and resuscitation: electrical stimulation of certain areas of the brain; treatment of Parkinson's disease and epilepsy, also for electrophoresis. A pacemaker that stimulates the heart muscle with a pulsed current is used for bradycardia and other cardiac arrhythmias.

electrical safety

Main article: electrical safety

It includes legal, socio-economic, organizational and technical, sanitary and hygienic, medical and preventive, rehabilitation and other measures. Electrical safety rules are regulated by legal and technical documents, regulatory and technical framework. Knowledge of the basics of electrical safety is mandatory for personnel servicing electrical installations and electrical equipment. The human body is a conductor of electric current. Human resistance with dry and intact skin ranges from 3 to 100 kOhm.

The current passed through the human or animal body produces the following actions:

thermal (burns, heating and damage to blood vessels);
electrolytic (blood decomposition, violation of the physico-chemical composition);
biological (irritation and excitation of body tissues, convulsions)
mechanical (rupture of blood vessels under the action of steam pressure obtained by heating with blood flow)

The main factor determining the outcome of electric shock is the amount of current passing through the human body. According to safety measures, electric current is classified as follows:

safe a current is considered, the long passage of which through the human body does not harm him and does not cause any sensations, its value does not exceed 50 μA (alternating current 50 Hz) and 100 μA direct current;
minimally perceptible human alternating current is about 0.6-1.5 mA (alternating current 50 Hz) and 5-7 mA direct current;
threshold relentless called the minimum current of such a force at which a person is no longer able to tear his hands away from the current-carrying part by an effort of will. For alternating current, this is about 10-15 mA, for direct current - 50-80 mA;
fibrillation threshold is called an alternating current (50 Hz) of about 100 mA and 300 mA of direct current, the effect of which is longer than 0.5 s with a high probability of causing cardiac muscle fibrillation. This threshold is simultaneously considered conditionally lethal for humans.

In Russia, in accordance with the Rules for the technical operation of electrical installations of consumers and the Rules for labor protection during the operation of electrical installations, 5 qualification groups for electrical safety have been established, depending on the qualifications and experience of the employee and the voltage of electrical installations.

How can I explain to a child what electricity is if I don’t understand it myself?

Svetlana52

You can very simply and clearly show what electricity is and how it is obtained, for this you need a flashlight that runs on batteries or a small lamp from a flashlight - the task is to get electricity, namely to make the light bulb light up. To do this, take a potato tuber and two copper and galvanized wires and stick it to the potato - use it as a battery - plus on the copper end, minus on the galvanized end - carefully attach it to a flashlight, or a light bulb - it should light up. To make the voltage higher, you can connect several potatoes in series. It is interesting to conduct such experiments with a child, and I think you will also enjoy it.

Rakitin Sergey

The simplest analogy is with water pipes through which hot water flows. The pump presses on the water, creating pressure - its analogue will be the voltage in the mains, the analogue of the current is the flow of water, the analogue of electrical resistance is the diameter of the pipe. Those. if the pipe is thin (high electrical resistance), then the trickle of water will also be thin (small current), in order to draw a bucket of water (get electrical power) through a thin pipe, you need a lot of pressure (high voltage) (therefore, high-voltage wires are relatively thin, low-voltage wires are thick, although the same power is transmitted through them).

Well, why is water hot - so that the child understands that electric current can burn no worse than boiling water, but if you put on a thick rubber glove (dielectric), then neither hot water nor current will burn you. Well, something like this (except perhaps here - water molecules move in pipes, in electric wires - electrons, charged particles of atoms of the metal from which these wires are made, in other materials, such as rubber, electrons sit firmly inside the atoms, they cannot move can, therefore, such substances do not conduct current).

Inna interviewed

I just wanted to ask the question "What is electricity?" and got here. I know for sure that no one still knows how it happens that when a switch is turned on in one place, a light bulb instantly lights up in another (hundreds of kilometers away). What exactly is running through the wires? What is current? And how can it be explored if it beats, an infection))?

And the child can also show the mechanism of this process on potatoes, as advised in the Best Answer. But this number will not work with me!

Volck-79

Look how old he is. If 12-14 and he doesn't understand a belmez, then, excuse me, it's too late and hopeless. Well, if it’s five or eight years old (for example) - explain that all these things (holes, wires, all sorts of other beautiful objects) bite great, especially if you touch them, lick them, put your fingers in something, or vice versa poke.

Anfo-anfo

My daughter is 3 years old. At one time, I simply told her that it was dangerous, and now she does not climb into the sockets. And later I will explain that electricity is such an energy that gives light, from which a TV, computer and other equipment works. When she becomes a schoolgirl, she will study physics in more detail.

Ynkinamoy

you know many ways to explain to a child that it’s impossible, that it’s dangerous, I think that the child should be taught this, point to the rosette and say it’s impossible for you to go. If the child is still interested and he really wants to climb there, you need to install special if the child could not stick a finger or something metallic there, well, it’s best to use props and teach that it will hurt wow, that you can’t do it that it’s very bad that it will be bad for mom dad if he does it, bring to the child that you can’t do this, and use props. everything will be fine

Ksi Makarova

Now is the "age of the advanced Internet", ask any search engine a question, you can even with the wording "how to explain to a child what electricity is"))

Answering the tricky questions of my growing son, I managed to study a lot of topics in this way - it’s good for the child and useful for parents.

Natalia Frolova
Lesson of the cognitive cycle "Electricity" for children 6-7 years old

Tasks:

Educational:

Summarize knowledge children about electrical appliances, about their purpose in everyday life;

introduce the concepts« electricity» , « electricity» ;

introduce with the rules for the safe handling of electrical appliances.

Educational:

Develop the ability to work with models;

Develop a desire for search cognitive activity;

Develop mental activity, curiosity, the ability to draw conclusions.

Educational:

Cultivate interest in knowledge of the surrounding world;

Used media objects: poems, games, photos electrical appliances; electronically-educational resources: presentation « Electricity» , cartoon.

Used equipment: projector, screen, laptop, sports equipment: ball.

preliminary work: conversations, watching cartoons of Aunt Owl.

vocabulary work: activate adjectives, nouns, generalizing words in speech. Build and enrich vocabulary electricity, electrical appliances, trough, washboard)

LESSON PROCESS

I. Motivation

Music sounds.

caregiver: - Hello guys. Today we will talk about electricity, about safety in the house, let's play interesting games and learn how electricity appears in our homes.

II. caregiver: - Listen to the poem

We love our house very much

Both cozy and familiar.

But not everyone could

Do a lot of things.

We need to clean the house

cook, wash,

And ironing clothes...

How to cope with all the work!

And it's wonderful that now

We have helpers.

They make our work easier

Save our time.

caregiver: - What assistants are mentioned in the poem?

caregiver: - And now let's imagine that we are in a time when a person still knew nothing about electricity, and hence about electrical appliances he did not know and did not think. But he cooked his own food, washed his clothes and cleaned his house.

III. TALK ABOUT DEVICES "What is, what was"

caregiver: Let's talk about what helped the hostess before, and what now.

caregiver: - What is this? (on the slide screen - trough)

Children: trough, washing board.

caregiver: - That's right, it's a trough. What do you think they did in it?

Children: washed

caregiver: - And how does your mother erase now? What helps her?

Children: washing machine

caregiver: - What it is?

Children: broom

caregiver: - What is it for?

Children: clean dirt, sweep the floor

caregiver: - And what now helps to clean the house instead of a broom?

Children: vacuum cleaner

caregiver: - Right. See what's shown here?

Children: iron

caregiver: - What is it for?

Children: iron clothes

caregiver: - Look what the iron used to be. It is heavy, coals were put into it and while they were hot, they stroked. Look at what iron has become now. It is lightweight, comfortable and fast ironing.

caregiver: - What is this?

Children: oven, oven

caregiver: What do you think it was for?

Children: cook food, warm up, warm the house

caregiver: - What appliances are used in our time instead of the oven?

Children: microwave, electric stove, electric heater

caregiver: - What is this?

Children: candle

caregiver: What was it for?

Children: light up the room

caregiver: - What device replaced the spark plug?

Children: lamps, chandeliers

caregiver: - Well done, coped with the task. Now you know how many devices a person has improved, thanks to electricity.

caregiver: - And what do you think it is necessary for everyone to electrical appliances started working?

Children: electricity, current, wires

caregiver: - Quite right. All appliances run on electricity. But before I tell you where it comes from electricity Let's loosen up a bit.

caregiver: - Get out on the carpet. Get in a circle. I'll call electrical appliance, and the one who gets the ball in his hands will be told what actions he performs (iron, hair dryer, microwave, refrigerator, kettle, vacuum cleaner, fan). And now I will name the device that I used before, and you you will call it than it has been replaced in our time (candle, trough, broom).

caregiver: - See how many electrical appliances surrounds us. They are our best helpers. All of them make our life convenient and varied. Without them, it would be difficult for a person. All of these devices operate on electricity.

caregiver: - And now the task such: without turning the body, only turning the head, look around for pictures with the image electrical appliances(children find pictures with their eyes and name them).

caregiver: - Let's continue the conversation about electricity. Sit on chairs.

IV. TEACHER'S STORY "Where does it come from ELECTRICITY»

caregiver: - And who knows where it comes from electricity(answers children)

caregiver: - Electric current is generated at high power power plants. To obtain electricity, such stations use steam, sunlight, water and wind (slide show with