Clase de electricidad - Contenido educativo
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Se explica qué es la electricidad, las magnitudes eléctricas, elementro s de un circuito, la ley de OHM
Hello, guys. As you remember, we are in the electricity unit. We have started this unit already in December. But, well, I know that Christmas has passed and everything. So, before we continue with the unit, I'm going to remind you what we have seen, okay?
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and I know that we used another presentation in December and it was fine
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but I think this this presentation is more complete and well I think it's
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going to be easier for you to to understand the electricity unit okay so
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So here we go.
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The first thing that we need to remember is what is electricity.
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Remember that the first day I told you that matter is formed by atoms.
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You remember matter means materia and materia is anything.
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You are matter, myself is matter, an animal is matter, an object is matter, everything
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that you know, that everything that you can touch is matter, okay?
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This matter is formed by very small particles
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that are called atoms.
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And they have, they contain inside smaller particles
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with electrical charges that are called atoms.
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Remember that?
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We have outside electrons that are charged negatively
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and inside protons that are charged positively
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and neutrons that are charged,
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but that don't have a charge, okay?
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This charge create forces between them
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that can be attraction or repulsion
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according to the value of the charge, remember?
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If we have different charges,
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we are going to get an attraction
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and we have equal charges,
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we are going to get a repulsion, repulsion and repulsion.
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It doesn't matter if the charges are positive or negative,
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we're going to have repulsion.
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So what is electricity?
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here look look at this picture we have different atoms that are together this
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is what it happens with matter in mind is your arm your head your feet your
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foot so we have the atoms very close together and electrons are moving from
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one from this atom to this to the other from the other to the other and the
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movement of these electrons with the atoms is electricity so if I ask you
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So, what is electricity? Electricity is the movement of an electron from one atom to another, right? Okay. However, well, we have seen that electrons travel from one atom to another, okay?
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But if we want, for example, electrons to travel from a battery to a light, we are going to need a wire made of a material that allows the pass of the electrons.
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These materials that allow the pass of the electrons are called conductors.
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And we have metals or water.
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They transmit electricity.
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Remember the wires are normally made of copper
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because it's a very good conductor.
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They allow the pass of the current.
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Other materials don't allow the electrons to move.
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These are called insulators, for example, wood or plastic.
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In those materials, if we put imagine a battery
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and a light and we put a wood in between,
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electricity is not going to pass, okay?
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They are insulators.
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Okay, remember we did this experiment.
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We created static electricity.
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Here we can also see the repulsion and attraction rules.
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We got our sweater and we got a pen.
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We wrapped the pen on the cloth.
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So what happened was that the electrons,
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the negative charge of the sweater went to the pen, okay?
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pen okay and then when we put the pen when we touch the pen with the paper and the positive
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charges of the paper are going to travel and meet within with the pen because they are attracted
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they have different charges we have the electrons of the pen here and the positive charges of the
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of the of the paper and they are going to be attracted because they have different
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sign however the negative part of the paper are going to be repelled did you
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remember with experiment not all the paper was attached to the pen not all
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the paper only one part the part that was attached was only the part that had
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different charges okay remember that okay so how electricity is created and
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transform remember that a battery the batteries that we have been using in our
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experiments has a pole with negative charge and when we connect well the
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battery has a pole with more negative charges so when we connect them we
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connect the negative charges of a battery we create a balance we create we
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We connect the charges and start moving
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in order to balance themselves.
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We can read the electrical current.
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So the flow of the electrons go from the negative pole
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to the positive creating electrical current
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because of this difference, because of the balance.
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Okay, so here we have a circuit.
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We have our battery and one of our lights, a wire
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and inside the wire is the movement of the electrons.
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So we have the battery.
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they have, well, the battery has energy
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and energy is going to allow the electrons to travel.
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They are going to go outside the battery.
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They're going to go outside from the negative pole.
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They're going to travel
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and they are going to go back to the battery,
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to the positive pole.
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And the movement is creating electrical current.
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Okay, remember that what we have seen in practice one
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is that when the electrons travel along the wire
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and if in the path they encounter something,
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for example, a bulb, the electrons touch the bulb,
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the bulb is going to light.
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Okay, if we don't have a bulb but we have a fan,
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the fan is going to move.
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If we have a motor, it's going to move.
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If we have a toaster, for example, it's going to work.
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So the electricity is created with the battery
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or with electrical power
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and it's transformed into calorific energy,
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mechanical energy, light energy, magnetic energy and so on.
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And that is the reason why the light,
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why the bulb worked.
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Okay, so imagine we have the atoms
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and the electrons travel.
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Okay, travel inside the wire.
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So electrical current, electric current is the displacement
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of the electrical charges through the matter, okay?
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Remember in the summer, we also see the voltage.
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Well, the electron needs energy to be able to move
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through a material, this is the voltage.
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Okay, so the battery has an energy
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that is called the voltage.
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And the voltage is the energy per charge unit
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that makes them to flow in through a material, okay?
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We have the battery here.
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It has energy is going to impulse the electrons
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to go outside and to travel along the wire.
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This magnitude is measuring volts, okay?
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And with the voltage,
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it happens something similar to water, okay?
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If we have higher voltage,
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imagine that, well, this is the battery.
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we have a lot of electrons and if we open the wire,
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we are going to have more pressure,
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more water pressure and more electrons here.
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If the voltage is lower or the water is lower,
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we are going to have less pressure here
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and less water here, less electrons.
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That happens the same with the batteries.
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If we have a higher voltage,
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more electrons are going to travel.
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We have lower voltage, less electrons are going to travel.
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That's what it happened in practice one.
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with different batteries.
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The battery with the highest voltage,
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the light bulb was,
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the light was stronger
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than the battery with a lower voltage.
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We also have another magnitude, which is called intensity.
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Okay, the intensity is the amount of charges
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that goes through a conductor.
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The amount of electrons is measured in amperes.
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For example, here, there are a lot of electrons.
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we have higher intensity.
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We have here less electrons, we have lower intensity.
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And resistance, this is another magnitude.
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Remember that in December,
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we were discussing about resistance.
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I was telling you that you were electrons,
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that you were in a classroom
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and you wanted to travel from one classroom to another.
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And remember that I told you that I was a resistance
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and I was in the middle of the door.
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So what happened?
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if i'm super fat uh not many people are going to
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go through the door right because i i don't allow you to pass
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however if i'm a slimmer more electrons are going to pass
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that's what it happens with electricity we if we have we got if we have higher
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resistance we have more elements that are going to
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impede the pass of the current okay the
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resistance is the opposition of the movement however the if the resistance is lower
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uh more electrons are going to pass it's measuring ohms
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okay now that we have seen the three magnitudes uh we have the ohm's law the ohm's law is the
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load that relates uh the three magnitudes the intensity the voltage and the resistance
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this formula is very important that you learn and this table is very important that you learn it
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this is going to be on the exam all right we have magnitude and the symbols of it voltage
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intensity and resistance have those symbols and the units how they are measured are volts
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amperes and ohms and the symbols of the units okay please don't um try to distinguish between
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the symbol of the magnitude and the symbol of the unit for example my name is monica and the symbol
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of my name is an m however if i want to know my weight is going to measure in kilograms and the
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symbol is going to be k okay even though my name and my wage are part of myself uh are different
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things we cannot measure my name with an m but we can measure my wage with a with a k that happens
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the same we have the name of a magnitude and the name has a symbol and how we measure that
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magnitude has another symbol okay all of that is what we have seen in december okay now we are
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going to learn what electric circuit has okay we have built some electric circuits in practice one
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and practice two and we are going to see which parts they have this is an electrical circuit
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we have generators control elements receptor conductor and protection elements
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we are going to see what are they okay okay a generator is a component that generates current
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okay a battery the symbol is this so if we draw um
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if we draw a circuit we need to draw it like this
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the battery okay receptors are um with the different objects that
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are going to receive the electrons okay and they're and are going to do
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something we have the valve for example the symbol is like that if we want to
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draw a bulb on a paper we need to draw it like that it produces light when it gets the electrons
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a motor it produces motion resistor well here it says it produces heat because some resistors
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produce heat okay but other resistors just opposed to the to the to the current okay
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we have a buzzer it produces sun you need to learn the different components and the different
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symbols and why are they used for okay we also have concert components we have
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a switch okay controls the flow of the current so when the switch is closed is
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going to allow the pass of the electrons you can see for example you're there we
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have electrons here traveling did it if this is closed they can pass they don't
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have any hole they can pass however if we open it they are going to be a hole
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and electrons are going to be stuck here, they are not going to be able to pass.
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A three-way switch, a commutador, is the same as a switch but with two circuits,
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so it alternates the flow of the current between two circuits. If we close this switch here,
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that means that the electrons are going to pass from here to this circuit and if we close it in
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in this direction, electrons are going to pass from here
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to this direction.
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A push button, it controls the flow of the current
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as we have seen in practice two.
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When we press the button, we press it,
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it happens something similar to the switch.
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If we press it, the current is going to flow.
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Can you see?
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It flows.
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However, if we don't push it,
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it's going to be very far away.
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Imagine that it's a bridge.
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If the bridge is not here, it's very far,
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you're not going to pass.
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However, if it's close, it's going to pass.
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Like what it happens with the flow of the current.
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And protection components.
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They protect the circuit and we have a fuse,
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something like that, and this is a symbol, okay?
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So I want you to do exercise seven.
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I want you to draw the following circuit
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using electric symbols.
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And exercise eight,
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go the following circuit using electric symbols.
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If you have any question, just let me know.
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You can text me on the chat.
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I will be there to answer to your questions.
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- Idioma/s:
- Autor/es:
- Mónica Gallego Peñalva
- Subido por:
- Monica G.
- Licencia:
- Todos los derechos reservados
- Visualizaciones:
- 5
- Fecha:
- 26 de marzo de 2024 - 12:25
- Visibilidad:
- Clave
- Centro:
- IES PEDRO SALINAS
- Duración:
- 16′ 05″
- Relación de aspecto:
- 1.58:1
- Resolución:
- 1424x900 píxeles
- Tamaño:
- 38.57 MBytes