From physics course known that one of the characteristics of a body is its ability to do the job, since the latter is not nothing but a transformation of one form of energy into another (for example, the potential into kinetic energy).It should take account of the famous law of conservation of energy, formulated in the XVIII century MVLomonosov whereby energy never does not disappear, it merely modified, takes a different form.The foregoing equally applies not only to solids but also to other types of material, including the electrical current.
electric current, as has long been proven - is directed movement of charged particles.Moving on a specific circuit portion, the particles form an electric field which performs the work.Employment of an electric current - it is the amount of energy that must be expended to move the charge for this circuit.However, not all the work of the current useful and effective.Rather significant part of the energy is spent on it, to overcome the resistance of the electric charge of elementary particles in the conductor and the source circuit.
Work electric current, the formula is as follows from the above given text A = U • Q, is an essential characteristic of this special form of matter.In this formula, U is the potential difference (voltage) on the circuit, and Q - quantification of charge transferred to this portion.
itself, however, operation of the electric current would not represent special interest, if not found a pattern, linking this work and the amount allocated in this heat.This pattern almost simultaneously opened two well-known physicist - Lenz and Jody Prescott, and therefore the law in the scientific community received the name of "the law of Joule."According to this law, it turns out that the amount (or power) of heat, which is allocated to a certain extent during the flow therethrough of charged particles is directly related to the product of the field strength at the density flowing through the portion of the electric current.This law is of great importance for the calculation of electricity losses during transmission through wires over great distances.
Work electric current is directly related to another important value - power.Under current power physics realize quantitative conversion characteristic and the rate of transfer of electric energy.Power is measured in kilowatt-hours, while the operation of the electric current - in joules.
For maximum power current from a particular source, you must take into account the characteristics of the source, and that the resistance of the internal and external circuit must be compatible with each other, otherwise the whole of the work undertaken will be spent on overcoming the difference in resistance.
Work electric current is the most important physical characteristics that must be considered in almost all industries, as well as in the production and transmission of energy over long distances.
