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ELECTRIC CIRCUITS - Contenido educativo

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Subido el 1 de septiembre de 2018 por Isabel L.

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Today we are going to review electricity. 00:00:04
You should understand everything because we are going to study electricity this year in this course but a little bit more complicated. 00:00:09
So it's very important that you have learned the contents of the first episode in order to improve 00:00:24
them and reach the level of the second episode. So this is the main reason why we are going to 00:00:38
review these contents. This is the list of things that you should 00:00:49
study and you should review. I strongly believe that all of them know all of 00:01:01
them so I think it's just only to remember these contents. 00:01:09
Matter is a mixture of different things, indeed it is not homogeneous, indeed it is heterogeneous. 00:01:23
And its components are composed of put components that are formed by molecules. 00:01:38
The molecules can be obtained by combining, by linking the different atoms in more or less defined proportions. 00:01:52
The atoms are composed of a shell with electrons, particles with mass and negative charge, and a nucleus consisting in protons, particles with positive charge and mass, and neutrons, particles that only have mass. 00:02:03
So, therefore, the mass and the church are intrinsic characteristics of the matter itself. 00:02:22
And we also know that between two masses there are always attractive forces, 00:02:32
But, on the other hand, between two churches we can have attractive if the churches are of different signs 00:02:41
or repulsion if the churches are opposite signs. 00:03:00
But electrical current is indeed the movement of electrical charge, so taking into consideration 00:03:09
that electrical charge is just only a characteristic of the matter, you need something, a carrier 00:03:33
for this characteristic and the carrier can be, for example, electrons that we have already 00:03:43
described in this presentation, but we can also have other kinds of carrier. 00:03:54
One of these kind of carriers could be holes. 00:04:03
Holes are when you lose an electron. 00:04:08
If you haven´t an electron you have a hole and a hole is a carrier of a positive charge. 00:04:18
And finally, you can also carry an electric charge using ions. 00:04:30
The ions are the result of an atom which has more electrons than an atom. 00:04:40
So negative electricity charge and they are called cations, sorry, anions, or they can 00:04:56
have less electrons than neutral atoms. 00:05:13
In this particular case, they are called cations. 00:05:21
Apart from this, matter can be insulator or insulators or conductors. 00:05:31
They are conductors if they let that the charge move into themselves, if they don't allow 00:05:46
the movement of the electrical charge, they are insulators and it's very difficult to 00:06:01
establish a limit between insulators and conductors. So a substance could also be 00:06:10
semiconductor. Well, if we want to study the movement of the electrical 00:06:24
church you need to know the principal electrical magnitudes. This slide shows them. 00:06:39
You can see the definition of the magnitudes, the mathematical formula and the unit and the symbol. 00:06:52
Between them there are three which are the most important, which are intensity, the charge per unit of time, 00:07:03
the unit of intensity is amperio, 00:07:17
and the voltage, which is the energy you have to use to move a charge between two points in the electrical field 00:07:23
which unit is Volt, and a resistance, which is the opposition of the material, of the matter, to the current, to the movement of charge, and its unit is Ohm. 00:07:41
There are also others important, such as electrical energy, which unit is J, and electrical power, which unit is V. 00:08:05
And I think you should study very carefully and if you have any doubts you should tell me in order to explain it more. 00:08:20
But I think all of you have known all these electrical magnitudes. 00:08:35
So, electric circuits transform electrical energy into other kinds of energies 00:08:42
and it needs different parts, it needs different components, physical components that you can touch, something, hardware that you can touch. 00:08:59
So these components, these parts of circuits can be classified into four main groups 00:09:12
which are generators, it provides energy, electrical energy 00:09:25
active elements, which transform electrical energy into other kinds of energy 00:09:32
controls and maneuvers which are responsible for the manipulation of the circuit, 00:09:39
protection elements and cables. 00:09:51
Here you have a list of different elements but obviously 00:09:58
and they are their symbols, because symbols for electrical components have been known, 00:10:07
have been studied, because it's an universal language. 00:10:22
Here you can see, for example, pulp, which is light pulp, is very interesting, very important. 00:10:30
You also have, for example, batteries, which gives you power, and different kinds of input 00:10:41
devices, which are switches, different switches, that you can see some of them 00:10:59
and others. Motor, it is important also, fuse, it's important to study these 00:11:07
symbols. Well, as I said before, the three more important electrical magnitudes 00:11:19
are voltage intensity and resistance ohms show that the relationship between 00:11:30
these three magnitudes is that the slide show it is voltage is the 00:11:46
multiplication of resistance and intensity and this law is very important 00:12:02
because we can use it for all of the different exercises in electrical circuits. 00:12:15
The slide shows the simplest exercise you should solve. 00:12:32
In it you have a battery of 5 volts and a light bulb and it also shows an emitter and a voltmeter. 00:12:48
The emitter measures the electric intensity, which is 50 milliamperes. 00:13:09
So, by using Ohm's law, you can calculate the value of the resistance, as you can see here in this image. 00:13:24
So, it's very important to understand this exercise because we will use and we will solve exercises a little bit more complicated in this level. 00:13:37
Finally, we are going to revise other effects which are associated with circuits, electrical circuits. 00:14:04
One of them is Joule's effect. Joule's effect is a consequence of the resistance of the materials. 00:14:27
and it consists in the transformation of part of the electric energy into heat 00:14:43
And this energy loses and you can't use this energy. So it seems to be a negative effect. 00:15:01
Apart from Joule's effect there are two other effects which are very interesting. 00:15:20
One is the creation of magnetic fields because of the movements of electric charge. 00:15:29
and other is the production of electric current because of the movement of the changes in the time of some magnetic flux. 00:15:46
Both of them are used in electric machines, motors, generators and so on. 00:16:07
And we will study them this year. 00:16:20
And this is the end of the review of electricity and I hope it is useful. It could be useful. 00:16:30
Idioma/s:
en
Autor/es:
ISABEL LAFUENTE
Subido por:
Isabel L.
Licencia:
Reconocimiento - No comercial
Visualizaciones:
350
Fecha:
1 de septiembre de 2018 - 20:32
Visibilidad:
Público
Centro:
Sin centro asignado
Duración:
16′ 55″
Relación de aspecto:
1.78:1
Resolución:
1920x1080 píxeles
Tamaño:
197.24 MBytes

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