What is an electric current: directional motion
Everybody knows by experience what an electric current is,but not all understand the physical nature of this phenomenon, especially if during the school course of physics this is not interested. And for many school children, physics textbooks seem to be vaguely written. Let's try to correct these errors by describing this phenomenon simply.
The collective farm is at work
The very word "current" means that it is a question ofmovement, rather than a static phenomenon. What is an electric current? It's just a directed movement of charged particles in a conductor or an electrolyte. Classical conductors - objects from metals. They are always considered dangerous, remember this if you need to push the victim from a current source. The nature of the electric current in metals is associated with a special property of matter. The fact is that electrons in metals are quite free and represent something like a collective economy. Therefore, in this category of substances, the current is carried out very easily, it is easy to achieve directed motion of the particles.
Events in solutions
The electric current is also well transmittedsolutions of charged particles - ions. At the same time, positively charged cation particles approach the cathode, the negative electrode, and the anion particles are the anion particles, whose charge is negative. Thus, a solution with negative and positive ions, that is, with electrolytes, is a good current conductor.
Why the variable?
Types of electric current - so oftenthe question on the exam is formulated. And in response, as a rule, they want to hear: "permanent or variable". What is the difference? The constant current moves in the same direction, the alternating current changes its direction. Why did I need an alternating current (namely, it is supplied in domestic service and in production?). The fact is that when using AC power, there is much less loss when transferring it via cable. Thus, electricity transmission becomes more economical.
Electricity and magnets
What is an electric current in nature? It was seen by everyone who saw lightning - a current of monstrous tension and strength. The person uses many properties of a current, for example, an opportunity to provoke the magnetic phenomena: in coils of inductance, motors and generators. It is the work of scientists-researchers that we owe the comfort of modern life.
Northerners see more
What is the electric current for a resident of the northerncountries? This is the cause of the northern lights, a very spectacular natural phenomenon. Another natural example of electric current can be considered the so-called solar wind, which, strictly speaking, is the cause of the northern lights. This is the flow of particles from the corona of the sun. It also creates magnetic storms. This flow for the Sun is normal, but some people constantly feel these phenomena on themselves.
Electric current is also capable of causingthermal phenomena. Simple heating of working appliances is proof of this. And it's not just about appliances designed for heating, such as a boiler and a heater. Side effect - heating from electric current - occurs very often.
Electric current for many decades is trueserves man. But you have to be very careful with it. We pay tribute to hundreds of lives of electricity, every year, due to negligence, many people die. The current does not forgive mistakes!