ELECTRICITY STATIC

TRADUCCION IN CONTEX

LA ELECTRICIDAD Y LOS CIRCUITOS ELÉCTRICOS

Yo les voy hablar acerca de la electricidad y los circuitos eléctricos, los científicos han estudiado a la  electricidad durante mucho tiempo de manera que la palabra electricidad  en realidad proviene de la palabra ámbar  ya que se dieron cuenta que si este se frota podía generar una carga estática.

Alguna vez has ido a uno de esos toboganes de plástico, y has salido con un montón de electricidad  estática?

Y que es electricidad estática? Pues bien, aquí tengo un guante de goma ya que no tengo un globo por lo que yo voy a frotar este guante en mi cabeza una y otra y otra vez, realmente se puede escuchar la electricidad estática y lo que hace en realidad es atraer los electrones de mi cabello y poniéndolos en el guante de goma entonces en mi cabello hay menos electrones, y tendrá carga positiva y el guante tendrá una carga negativa, pero esta no va  a ninguna parte ya que esta allí estática a eso lo llamamos electricidad estática, y esta es la razón para que el cabello del niño este hacia arriba ya que cada uno de ellos tienen carga positiva porque está perdiendo electrones ya que cargas iguales se repelen, entonces todos los cabellos están empujándose el uno al otro y es por eso que si tocara un metal obtendría una descarga. Qué es eso? es simplemente el flujo de electrones donde la eléctrica estática se queda en un solo lugar. Pero la verdadera revolución se llevo a cabo cuando pudimos hacer circuitos, controlarlos y utilizar esa energía, para hacer las cosas antes se utilizaba la energía producida por vapor y cuando llegó la electricidad obtuvimos la revolución digital, es probable que no se piense en ello todo el tiempo pero en realidad toda la sociedad está a cargo de la electricidad, así que si buscas algo en google no te das cuenta de que se está consumiendo energía en ese punto, porque está haciendo una búsqueda y lo que hace google es ir a buscar en sus bases de datos  utilizando una gran cantidad de energía y eso es uno de sus costos más grandes lo que trata de hacer es que sus centros de datos sean tan eficientes como sea posible van a tratar de ponerlos hacia áreas donde pueden obtener energía barata y disponible.

Entonces ¿cómo funciona la electricidad? bueno esto no es una gran analogía pero si es una analogía que funciona bastante bien y me quedo con ella, ¿cómo almacenamos energía? bien una manera seria de la misma forma que almacenamos agua y esta se mueve en torno al estanque. En Finlandia existe un estanque grande de agua y este tiene debajo de la tierra una bomba y esta bomba bombea el agua hacia arriba y en la parte superior el agua está asentada y para que el agua se asiente ahí tiene una cierta cantidad de energía potencial, en una batería los electrones tienen una cierta cantidad de energía potencial y a eso lo llamamos empuje o energía almacenada o tensión. Bueno así que vamos a decir que quiero utilizar algo de esa energía, digamos que abro el grifo de mi casa o tiro de la cadena del baño, el flujo de agua a través de este circuito el agua fluye,  así de similar es el flujo de electrones en un circuito eléctrico, y si en un circuito existe una interrupción en el flujo de corriente a esto le llamamos un circuito abierto y todo el sistema no funcionaria y no avanzaría la electricidad por el circuito eléctrico.

Voy hablarles breve mente de circuitos eléctricos simples y les indicare como trabajan los diagramas eléctricos, existen algunos símbolos que debemos saber el primero es el de una batería, en una batería existe un lado positivo y un negativo el lado derecho de la batería es el lado positivo, es el que tiene un  pequeño bulto y al otro lado va a tener el lado negativo, en el símbolo vamos a tener una parte superior más larga positiva y una inferior más pequeña negativa. ¿Qué es un cable? un cable simplemente va hacer una línea en un circuito eléctrico por lo que si existen dos cables conectados en un circuito uno positivo y otro negativo se puede decir que la electricidad puede fluir a través de ese punto. Lo que realmente detiene el movimiento de la electricidad se llama resistencia y aquí están algunos conceptos de resistencia, si puedes mirar las bandas de color en el puedes saber cuánta resistencia tiene una resistencia lo que hace es impedir el flujo de electrones o el paso de ellos, el símbolo de la resistencia se lo representa con líneas hacia arriba y hacia abajo y conduce energía a ambos lados. 

A continuación tenemos lo que es una bombilla de luz. Para que pueda funcionar en realidad la electricidad deberá fluir por la parte inferior de la bombilla ya que en la parte inferior hay un poco de metal por lo cual va a fluir hacia el lado de afuera y está conectado toda la trayectoria interna de la bombilla a través de un filamento de alta  resistencia. Y así desprende calor y luz, dibujare la forma de una bombilla para mostrar que está conectado todo el camino, hay que dibujar un bucle y luego se dibuja el bulbo alrededor del exterior. A continuación tenemos lo que es un interruptor, un interruptor es simplemente una apertura en el circuito. 

Entonces, si es un interruptor cerrado lo tendríamos como este. Y así sería un interruptor abierto. Esto sería un interruptor cerrado y la electricidad fluiría por allí. Pero no podría fluir a través de un interruptor abierto la electricidad no es capaz de moverse a través del aire  ya que es una cantidad casi infinita de resistencia. Lo último que tenemos es un potenciómetro, un potenciómetro funciona así. Tiene una flecha la cual indica que se puede variar su valor de resistencia. Con el potenciómetro lo que podemos variar es la cantidad de electricidad que se mueve a través de él. Si alguna vez has usado un atenuador en su casa es como un  interruptor ¿Cómo funciona? estamos girando la cantidad de electricidad que puede moverse a través del potenciómetro y así estamos dejando mas electricidad o corriente. 

Ahora lo que toca hacer es un poco de práctica y aquí tengo algunas fotos. Aquí tenemos una batería simple, y un foco, voy a dibujar mis circuitos al lado  izquierdo tan solo dibujare mi batería primero justo aquí es el extremo positivo. Ahora estoy  dibujando una bombilla de luz y este tiende a volver a la batería y entonces le ponemos un bulbo así y esto es lo que sería un circuito eléctrico. Tengo una batería este sería el extremo positivo y el otro el negativo la electricidad va afluir a través de este bucle y esto produce la luz de la bombilla, este es un  circuito cerrado ya que va por todo el camino del bucle. Vamos a tener una serie de luces. Dibujare mi batería, aquí  luego se conecta los cables por lo que obtenemos tres conexiones así que voy a ir de la parte superior, a la parte inferior y así sería mi primera conexión. 

Si tiene un interruptor cerrado habría flujo de corriente y se regresa a la batería mi siguiente bucle tiene la mismos parámetros así que tiene un interruptor que va a través de la bombilla y luego vuelve y tenemos mi tercer bucle, existe un interruptor abierto  y tiene la bombilla de luz y luego vuelve a la batería ya si esto sería un circuito en paralelo. 

La electricidad puede ir todo el tiempo alrededor del circuito, cuando tenemos un interruptor abierto la electricidad no puede ir a través de un circuito abierto a esto le llamamos un cierta cantidad de resistencia ¿así que la electricidad donde tendrá que ir? tiene que ir a través de los otros lazos y las luces se van a encender porque la electricidad se va a mover a través de él pero la electricidad no puede pasar por aquí así que no hay que conectarle en ese punto, pero tenemos un procesador esto tiene electricidad que sale de aquí este sería el extremo positivo y el otro lado seria el extremo negativo a esto se le llama  un protoboard y así es la manera de conectarlos en el protoboard horizontalmente y verticalmente. Tenemos nuestra batería aquí así que voy a ir del lado negativo y luego al lado positivo. Tenemos una bombilla de luz que es un poco más grande, se puede ver que eso va a través de la bombilla de luz y baja al siguiente nivel donde tenemos un resistor y luego parece que lo siguiente que tenemos es un potenciómetro esto va a ser un  resistor variable y luego va conectado a mi batería.

 ¿Cómo funciona este circuito?

Usted puede variar la cantidad de resistencia y así este circuito  entregara una variación de  corriente y la luz de la bombilla va a tener una luz brillante o tenue y esta resistencia es la encargada de disminuir la cantidad de corriente eléctrica para que no tengamos demasiada electricidad pasando por la bombilla de luz. Así que obtenemos otra vez que la electricidad es simplemente el movimiento de electrones.

MOST INFORMATION ABOUT ELECTRICITY

What is electricity?

Electricity is a vital part of our lives. It gives us light, cools and warms our homes, heats our water, and helps us cook our food. But do you really understand how it’s made and how it’s measured?

Electricity exists all around us in nature, from storms to sea life. Humans saw the potential to harness the earth's energy to generate electricity. Now we rely on it every day. In order to really understand what electricity is, take a look at the science behind electricity at the atomic level.

Electricity figures everywhere in our lives. Electricity lights up our homes, cooks our food, powers our computers, television sets, and other electronic devices. Electricity from batteries keeps our cars running and makes our flashlights shine in the dark.

Here's something you can do to see the importance of electricity. Take a walk through your school, house or apartment and write down all the different appliances, devices and machines that use electricity. You'll be amazed at how many things we use each and every day that depend on electricity.

But what is electricity? Where does it come from? How does it work? Before we understand all that, we need to know a little bit about atoms and their structure.

All matter is made up of atoms, and atoms are made up of smaller particles. The three main particles making up an atom are the proton, the neutron and the electron. 

Electrons spin around the center, or nucleus, of atoms, in the same way the moon spins around the earth. The nucleus is made up of neutrons and protons.

Electrons contain a negative charge, protons a positive charge. Neutrons are neutral – they have neither a positive nor a negative charge.

There are many different kinds of atoms, one for each type of element. An atom is a single part that makes up an element. There are 118 different known elements that make up every thing! Some elements like oxygen we breathe are essential to life. 

Each atom has a specific number of electrons, protons and neutrons. But no matter how many particles an atom has, the number of electrons usually needs to be the same as the number of protons. If the numbers are the same, the atom is called balanced, and it is very stable.

So, if an atom had six protons, it should also have six electrons. The element with six protons and six electrons is called carbon. Carbon is found in abundance in the sun, stars, comets, atmospheres of most planets, and the food we eat. Coal is made of carbon; so are diamonds.

Some kinds of atoms have loosely attached electrons. An atom that loses electrons has more protons than electrons and is positively charged. An atom that gains electrons has more negative particles and is negatively charge. A "charged" atom is called an "ion."

Electrons can be made to move from one atom to another. When those electrons move between the atoms, a current of electricity is created. The electrons move from one atom to another in a "flow." One electron is attached and another electron is lost.

This chain is similar to the fire fighter's bucket brigades in olden times. But instead of passing one bucket from the start of the line of people to the other end, each person would have a bucket of water to pour from one bucket to another. The result was a lot of spilled water and not enough water to douse the fire. It is a situation that's very similar to electricity passing along a wire and a circuit. The charge is passed from atom to atom when electricity is "passed."

Scientists and engineers have learned many ways to move electrons off of atoms. That means that when you add up the electrons and protons, you would wind up with one more proton instead of being balanced.

Since all atoms want to be balanced, the atom that has been "unbalanced" will look for a free electron to fill the place of the missing one. We say that this unbalanced atom has a "positive charge" (+) because it has too many protons.

Since it got kicked off, the free electron moves around waiting for an unbalanced atom to give it a home. The free electron charge is negative, and has no proton to balance it out, so we say that it has a "negative charge" (-).

So what do positive and negative charges have to do with electricity?

Scientists and engineers have found several ways to create large numbers of positive atoms and free negative electrons. Since positive atoms want negative electrons so they can be balanced, they have a strong attraction for the electrons. The electrons also want to be part of a balanced atom, so they have a strong attraction to the positive atoms. So, the positive attracts the negative to balance out.

The more positive atoms or negative electrons you have, the stronger the attraction for the other. Since we have both positive and negative charged groups attracted to each other, we call the total attraction "charge."

Energy also can be measured in joules. Joules sounds exactly like the word jewels, as in diamonds and emeralds. A thousand joules is equal to a British thermal unit.

When electrons move among the atoms of matter, a current of electricity is created. This is what happens in a piece of wire. The electrons are passed from atom to atom, creating an electrical current from one end to other, just like in the picture.

Electricity is conducted through some things better than others do. Its resistance measures how well something conducts electricity. Some things hold their electrons very tightly. Electrons do not move through them very well. These things are called insulators. Rubber, plastic, cloth, glass and dry air are good insulators and have very high resistance.

Other materials have some loosely held electrons, which move through them very easily. These are called conductors. Most metals – like copper, aluminum or steel – are good conductors. 

What is an Electric Circuit?

You might have been wondering how electrons can continuously flow in a uniform direction through wires without the benefit of these hypothetical electron Sources and Destinations. In order for the Source-and-Destination scheme to work, both would have to have an infinite capacity for electrons in order to sustain a continuous flow! Using the marble-and-tube analogy, the marble source and marble destination buckets would have to be infinitely large to contain enough marble capacity for a "flow" of marbles to be sustained.

Each electron advancing clockwise in this circuit pushes on the one in front of it, which pushes on the one in front of it, and so on, and so on, just like a hula-hoop filled with marbles. Now, we have the capability of supporting a continuous flow of electrons indefinitely without the need for infinite electron supplies and dumps. All we need to maintain this flow is a continuous means of motivation for those electrons, which we'll address in the next section of this chapter.

An important principle to realize here is that it doesn't matter where the break occurs. Any discontinuity in the circuit will prevent electron flow throughout the entire circuit. Unless there is a continuous, unbroken loop of conductive material for electrons to flow through, a sustained flow simply cannot be maintained.

 Electric potential is the amount of electric potential energy per unit of charge that would be possessed by a charged object if placed within an electric field at a given location. The concept of potential is a location-dependent quantity - it expresses the quantity of potential energy on a per charge basis such that it is independent on the amount of charge actually present on the object possessing the electric potential. Electric potential difference is simply the difference in electric potential between two different locations within an electric field.

To illustrate the concept of electric potential difference and the nature of an electric circuit, consider the following situation. Suppose that there are two metal plates oriented parallel to each other and each being charged with an opposite type of charge - one being positive and the other being negative. This arrangement of charged plates would create an electric field in the region between the plates that is directed away from the positive plate and towards the negative plate. A positive test charge placed between the plates would move away from the positive plate and towards the negative plate. This movement of a positive test charge from the positive plate to the negative plate would occur without the need of energy input in the form of work; it would occur naturally and thus lower the potential energy of the charge. The positive plate would be the high potential location and the negative plate would be the low potential location. There would be a difference in electric potential between the two locations.

Now suppose that the two oppositely charged plates are connected by a metal wire. What would happen? The wire serves as a sort of charge pipe through which charge can flow. Over the course of time, one could think of positive charges moving from the positive plate through the charge pipe (wire) to the negative plate. That is, positive charge would naturally move in the direction of the electric field that had been created by the arrangement of the two oppositely charged plates. As a positive charge leaves the upper plate, the plate would become less positively charged as illustrated in the animation at the right. As a positive charge reaches the negative plate, that plate would become less negatively charged. Over the course of time, the amount of positive and negative charge on the two plates would slowly diminish. Since the electric field depends upon the amount of charge present on the object creating the electric field, the electric field created by the two plates would gradually diminish in strength over the course of time. Eventually, the electric field between the plates would become so small that there would be no observable movement of charge between the two plates. The plates would ultimately lose their charge and reach the same electric potential. In the absence of an electric potential difference, there will be no charge flow.

The above illustration comes close to demonstrating the meaning of an electric circuit. However, to be a true circuit, charges must continually flow through a complete loop, returning to their original position and cycling through again. If there were a means of moving positive charge from the negative plate back up onto the positive plate, then the movement of positive charge downward through the charge pipe (i.e., the wire) would occur continuously. In such a case, a circuit or loop would be established.

A common lab activity that illustrates the necessity of a complete loop utilizes a battery pack (a collection of D cells), a light bulb, and some connecting wires. The activity involves observing the effect of connecting and disconnecting a wire in a simple arrangement of the battery pack, light bulbs and wires. When all connections are made to the battery pack, the light bulb lights. In fact, the lighting of the bulb occurs immediately after the final connection is made. There is no perceivable time delay between when the last connection is made and when the light bulb is perceived to light up.

The fact that the light bulb lights and remains lit is evidence that charge is flowing through the light bulb filament and that an electric circuit has been established. A circuit is simply a closed loop through which charges can continuously move. To demonstrate that charges are not only moving through the light bulb filament but also through the wires connecting the battery pack and the light bulb, a variation on the above activity is made. A compass is placed beneath the wire at any location such that its needle is placed in alignment with the wire. Once the final connection is made to the battery pack, the light bulb lights and the compass needle deflects. The needle serves as a detector of moving charges within the wire. When it deflects, charges are moving through the wire. And if the wire is disconnected at the battery pack, the light bulb is no longer lit and the compass needle returns to its original orientation. When the light bulb lights, charge is moving through the electrochemical cells of the battery, the wires and the light bulb filaments; the compass needle detects the movement of this charge. It can be said that there is a current - a flow of charge within the circuit.

The electric circuit demonstrated by the combination of battery, light bulb and wires consists of two distinct parts: the internal circuit and the external circuit. The part of the circuit containing electrochemical cells of the battery is the internal circuit. The part of the circuit where charge is moving outside the battery pack through the wires and the light bulb is the external circuit. In Lesson 2, we will focus on the movement of charge through the external circuit. In the next part of Lesson 2 we will explore the requirements that must be met in order to have charge flowing through the external circuit.

Req = R1 + R2 + R3 + … (series connections)

1/Req = 1/R1 + 1/R2 + 1/R3 + … (parallel connections)

QUESTIONS AND ANSWERS

   1. What is electricity?

       Electricity is the flow of electrons through a conductor.

   2. What is static electricity?

       Static electricity is an accumulation of electric charge on an insulated body.

   3. What is the purpose of developing an electric circuit?

       The purpose of developing an electric circuit is control electricity for a specific purpose.

   4. What is the function of the wire into an electrical circuit?

       The wire is the medium of transport of electricity and allows the flow of electrons to the        circuit.

   5. Where to find electricity?

       Electricity is present in everything around us.

   6. What is electrical resistance?

       Electrical resistance is the opposition to the passage of electrons.

   7. What is the filament of a light bulb?

      The filament opf a ligth bulb is a piece of metal into the bulb.

   8. What is a switch?

      Swich is an element used to turn on or off a circuit.
   9. How does a potentiometer work?

      Potentiometer is a resistor that varies its value by manually adjusting the intermediate 
      pin element.

 10. Why when you rub a balloon on your head generates static electricity?

      Because there is an interaction between atoms of globe and hair, so one will lose 
      electrons and the other will lose, and this flow of electrons is called static electricity.

11. Why it is important to the voltage source in an electrical circuit?

      The voltage source is important because it is responsible for feeding the circuit and 
      operating the items placed