Current determines the amount of charge passing through a cross-section per unit time.That is the formula that determines the physical quantity of current, expresses the ratio of the amount of the charge at the time of its passage in the chain.Thus, the current actual flow rate of said charge in an electrical circuit.If after a section of the conductor with a current passes in one second a charge of one Coulomb, the corresponding current is equal to one ampere.Since the unit is determined by the current.

Unit voltage

physical magnitude of the voltage is determined by the degree of inverting charge at the opposite pole of the circuit.In other words, the voltage across any portion of the chain is greater the greater the difference in the charges on the ends of the section.For example, the voltage across the capacitor plates is equal to the pro
duct of the electric field between the electrodes and the distance between them.Thus, the higher the field strength (the stronger it is), the greater the stress.

current proportional to the voltage

Thus, the voltage depends on the strength of the electric field.But as you know, it is the electric field and creates a current in the circuit, because of the acts charged in the Coulomb force, forcing them to move.Accordingly, the higher the Coulomb force, the greater the rate of charge and hence the current.Thus, both the current and the voltage is directly proportional to the electric field.

However, not all the charges flowing in the conductor due to the electric field, will reach its end.Some of them collide with atoms of the conductor material, and the mobility decreases.Moreover, the possibility of the conductor to conduct electrical current depends on the type of substance and its geometrical parameters.The longer you move the electron in the chain, the greater the likelihood that he will encounter on the ion conductor material.

In order to characterize the degree of attenuation of the electron mobility on the circuit, the resistance value is used.She is a constant of proportionality linking the current and voltage.This pattern is reflected in Ohm's law, which allows you to find the value of the current strength, if you know the applied voltage and the resistance of the current loop.