What is the current
For many centuries mankind has tried to understand what the current. Today, scientists have given a specific definition of this physical phenomenon. So what really is the current, and measured its performance?
What is the current
More from school physics course we know that electric current is considered to be nothing like the movement of particles having a charge in a particular direction, a particular guide. Such movement could occur should the presence of an electric field. At the same time, charged particles can occur everywhere due to the close contact that occurs between different substances.
Charges are able to make free movement between the various particles in the conductors or not be able to move in insulators. As conductors are metals, salt and acid solutions. An example of the insulator there is a lot of gas. Also don’t miss the electric charge of the ebonite, quartz, amber, some artificial materials: PVC, polyethylene, etc.
To measure current used by various settings, which include: voltage, power, resistance, power, frequency, etc. Consider the main ones.
The so-called physical quantity, measurable. It is equal to the ratio between the amount of electric charge that can pass through the conductor, or rather its cross section over a specified time interval with respect to the magnitude of this time period. Physics for measuring this quantity using a unit called Ampere (A).
The power of the current
The power is called the work done by the particles current on the resistance of electricity. The result of this work stands out the thermal energy. You can also say that the power current is the amount of heat energy released over a given period of time. In physics it is customary to measure capacity in units that are called Watts (W).
This concept defines the relationship of the work of the current, which is carried out in respect of a charge on a particular area the circuit breaker. Since the unit of measurement of charge is considered to be the Coulomb (C), and the work – Joule (j), to measure voltage use the unit 1/1kl, which is equal to 1 Volt (V).
Resistance to electricity
While conducting various experiments with electric current, Georg Ohm said that depending on the electrical circuits, the devices show different current flow. So was there proof that each conductor has its own resistance. For its calculation the length of the conduit is divided by the area of its cross section. The unit of measurement of resistance is considered to be Ohms.
AC and DC current
Already from the name it becomes clear that the constant current is called the one that regardless of external factors does not change direction and frequency. Since DC has no frequency, so adopted to consider it zero.
Accordingly, alternating current – current can change its magnitude and direction for a specified unit of time. Frequency referred to the number of cycles for a certain period of time. It is measured in Hertz (Hz).