Electric current — an ordered motion of charged

Electric current - an ordered motion of charged particles in a conductor. That it has arisen, it is necessary to create preliminary electric field under which action the aforementioned charged particles will start moving.

Characteristics Historically, it is assumed that the current direction coincides with the direction of the positive charges in the conductor. In this case, if the only charge carriers are negatively charged particles, the current direction opposite to the direction of electron motion. Speed of the directed movement of particles in conductors depends on a material of a conductor, weight and a charge of the particles, the surrounding temperature, the enclosed potential difference and makes size, much more smaller a velocity of light. Despite it, speed of distribution actually an electric current is equal to a velocity of light, that is speed of distribution of front of an electromagnetic wave.

Direct current Alternating current

Direct current The current, direction and which size poorly changes in time. Application The direct current is widely used in the technician: the overwhelming majority of electronic schemes as a food use a direct current. The alternating current is used mainly for more convenient transfer from the generator to the consumer. Sometimes in some devices a direct current will transform to an alternating current converters

Is the current direction and magnitude of which varies with time. ØPressure in alternating current networks will easily be transformed from one level to another by transformer application. ØThe alternating current is used mainly for more convenient transfer from the generator to the consumer. ØAsynchronous electric motors of an alternating current it is easier and more reliable than direct current engines.

The force and density current Current strength is a physical quantity, equal to the ratio of the charge last for some time through a cross-section to the amount of time. Power In the presence of a current in a conductor work against forces of resistance is made. This work is allocated in the form of heat. As capacity of thermal losses is called the size equal to quantity of allocated heat in unit of time.

The constant anode (collector) current proceeding when pressure of displacement is enclosed to an operating electrode.

Presentation on a theme the Electric current prepared by student 2 courses of a speciality 160901 Жеребцов Сергей