What is electric current? Conditions for the existence of electric current: characteristics and actions

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Electric current is an electrical charge in motion. It can take the form of a sudden discharge of static electricity, such as lightning. Or it could be a controlled process in generators, batteries, solar or fuel cells. Today we will consider the very concept of "electric current" and the conditions for the existence of an electric current.

Electrical energy

Most of the electricity we use comes in the form of alternating current from the electrical grid. It is created by generators that work according to Faraday's law of induction, due to which a changing magnetic field can induce an electric current in a conductor.

Generators have rotating coils of wire that pass through magnetic fields as theyrotation. As the coils rotate, they open and close relative to the magnetic field and create an electrical current that changes direction with each turn. The current goes through a full cycle forward and backward 60 times per second.

Generators can be powered by steam turbines heated by coal, natural gas, oil or a nuclear reactor. From the generator, the current passes through a series of transformers, where its voltage increases. The diameter of the wires determines the amount and strength of current they can carry without overheating or wasting energy, and voltage is only limited by how well the wires are insulated from ground.

It is interesting to note that the current is carried by only one wire, not two. Its two sides are designated as positive and negative. However, since the polarity of the alternating current changes 60 times per second, they have other names - hot (trunk power lines) and grounded (passing underground to complete the circuit).

Why do we need electricity?

There are many uses for electricity: it can light up your home, wash and dry your clothes, lift your garage door, boil water in a kettle, and power other household items that make our lives so much easier. However, the ability of the current to transmit information is becoming increasingly important.

When connecting to the Internet, a computer uses only a small part of the electric current, but this is something without which a modern personcan't imagine his life.

The concept of electric current

Like a river flow, a flow of water molecules, an electric current is a flow of charged particles. What is it that causes it, and why doesn't it always go in the same direction? When you hear the word flow, what do you think of? Perhaps it will be a river. It's a good association, because that's the reason the electric current got its name. It is very similar to the flow of water, only instead of water molecules moving along the channel, charged particles move along the conductor.

Among the conditions necessary for the existence of an electric current, there is an item that provides for the presence of electrons. Atoms in a conductive material have many of these free charged particles that float around and between the atoms. Their movement is random, so there is no flow in any given direction. What does it take for an electric current to exist?

The conditions for the existence of electric current include the presence of voltage. When applied to a conductor, all free electrons will move in the same direction, creating a current.

Curious about electric current

The interesting thing is that when electrical energy is transmitted through a conductor at the speed of light, the electrons themselves move much more slowly. In fact, if you walked leisurely next to a conductive wire, your speed would be 100 times faster thanelectrons move. This is due to the fact that they do not need to travel huge distances to transfer energy to each other.

Direct and alternating current

Today, two different types of current are widely used - direct and alternating. In the first, the electrons move in one direction, from the "negative" side to the "positive" side. The alternating current pushes the electrons back and forth, changing the direction of the flow several times per second.

Generators used in power plants to produce electricity are designed to produce alternating current. You probably never noticed that the light in your house is actually flickering as the current direction changes, but it happens too fast for the eyes to recognize.

What are the conditions for the existence of direct electric current? Why do we need both types and which one is better? These are good questions. The fact that we still use both types of current suggests that they both serve specific purposes. As far back as the 19th century, it was clear that efficient transmission of power over long distances between a power plant and a house was possible only at very high voltages. But the problem was that sending really high voltage was extremely dangerous for people.

The solution to this problem was to reduce the stress outside the home before sending it inside. To this day, direct electric current is used to transmit largedistance, mainly due to its ability to easily convert to other voltages.

How electric current works

The conditions for the existence of an electric current include the presence of charged particles, a conductor and voltage. Many scientists have studied electricity and found that there are two types of it: static and current.

It is the second that plays a huge role in the daily life of any person, as it is an electric current that passes through the circuit. We use it daily to power our homes and more.

What is electric current?

When electric charges circulate in a circuit from one place to another, an electric current is generated. The conditions for the existence of an electric current include, in addition to charged particles, the presence of a conductor. Most often it is a wire. Its circuit is a closed circuit in which current flows from a power source. When the circuit is open, he cannot complete the journey. For example, when the light in your room is off, the circuit is open, but when the circuit is closed, the light is on.

Current power

The conditions for the existence of an electric current in a conductor are greatly influenced by such a voltage characteristic as power. This is a measure of how much power is being used over a period of time.

There are many different units that can be used forexpressions of this characteristic. However, electrical power is almost measured in watts. One watt equals one joule per second.

Electric charge in motion

What are the conditions for the existence of an electric current? It can take the form of a sudden discharge of static electricity, such as lightning or a spark from friction with a woolen cloth. More often, however, when we talk about electric current, we mean a more controlled form of electricity that makes lights and appliances work. Most of the electrical charge is carried by the negative electrons and positive protons within the atom. However, the latter are mostly immobilized inside atomic nuclei, so the work of transferring charge from one place to another is done by electrons.

Electrons in a conductive material such as a metal are largely free to move from one atom to another along their conduction bands, which are the higher electron orbits. A sufficient electromotive force or voltage creates a charge imbalance that can cause electrons to move through a conductor as an electric current.

If we draw an analogy with water, then take, for example, a pipe. When we open a valve at one end to let water enter the pipe, we don't have to wait for that water to work its way all the way to the end of the pipe. We get water at the other end almost instantly because the incoming water pushes the water that is already in the pipe. This is what happens when there is an electric current in the wire.

Electric current: conditions for the existence of electric current

Electric current is usually viewed as a flow of electrons. When the two ends of the battery are connected to each other with a metal wire, this charged mass passes through the wire from one end (electrode or pole) of the battery to the opposite. So, let's name the conditions for the existence of an electric current:

1. Charged particles.
2. Explorer.
3. Voltage source.

However, not everything is so simple. What conditions are necessary for the existence of an electric current? This question can be answered in more detail by looking at the following characteristics:

• Potential difference (voltage). This is one of the prerequisites. Between the 2 points there must be a potential difference, meaning that the repulsive force that is created by charged particles in one place must be greater than their force at another point. Voltage sources, as a rule, do not occur in nature, and electrons are distributed fairly evenly in the environment. Nevertheless, scientists managed to invent certain types of devices where these charged particles can accumulate, thereby creating the very necessary voltage (for example, in batteries).
• Electrical resistance (conductor). This is the second important condition that is necessary for the existence of an electric current. This is the path along which charged particles travel. Only those materials that allow electrons to move freely act as conductors. The same ones atwhich do not have this ability are called insulators. For example, a metal wire will be an excellent conductor, while its rubber sheath will be an excellent insulator.

Having carefully studied the conditions for the emergence and existence of electric current, people were able to tame this powerful and dangerous element and direct it for the benefit of mankind.