How to find current strength

The power of the current is the movement of charged particles in one direction. It is possible to find current strength in practice using special instruments for measuring, and can be calculated using the already bred formulas, if there are source data.

The physical value that shows the charge, which passes for some unit of time through the conductor, is called the current power. The main formula according to which this force can be calculated: i \u003d q / t. That is, the relation that has passed through the cross section of the charge by the time interval during which electricity was accounted for, equal to the desired magnitude of I.

Decoding designations:

I - the designation of the power of electricity, is measured in amperes (A) or 1 pendant / second;
q - charge coming by conductor, unit of measurement pendants (CL);
t - the passage interval is measured in seconds (C).

Electricity can be constant - this is a current that contains a battery, or from which the mobile phone operation is supported, and the variable is what is in the outlet. The lighting of the premises and the operation of all electrical appliances occurs precisely by variable electricity. The difference between alternating current is that it is easier to transform, rather than permanent. A visual example of AC operation can be observed when the luminescent lamps are turned on: while the lamp turns on, the charged particles are moved forward - back - forward. This is the main essence of alternating current. By default, we are talking about measuring precisely this type of electricity, since it is most common in everyday life.

In accordance with the Ohm's law, the current strength can be calculated by the formula (for the electrical circuit section): i \u003d u / r, according to which the power of electricity is directly proportional to the voltage U, measured in volts, to the area of \u200b\u200bthe chain and inversely proportional to the R resistance of the conductor of this site expressed in Omah.

Based on the Ohm law, the calculation of the power of electricity in the total chain looks like this: I \u003d E / R + R, where

E - electromotive force, EMF, Volt;
R is an external resistance, Ohm;
r - internal resistance, Ohm.

Ohm laws are applicable to calculate DC, if it is also required to know the amount of force of the AC power, then the mined values \u200b\u200bshould be divided into root of two.

Main ways to determine the current force using instrument systems in practice:

The magnetoelectric measurement method, the advantage of which is the sensitivity and accuracy of the indications, as well as minor energy consumption. This method can be used only to determine the validity of the DC strength.
Electromagnetic is the foundation of the forces of alternating and constant currents by transformation from the electromagnetic field into a signal of a magnetomoomoomogen sensor.
Indirect, with a voltmeter is a voltage at a certain resistance.

To find current strength in fact, most often use a special device for this - an ammeter. This device is included in the ruptures of the electrical circuit at the required point of measurement of the power of the electric charge, which has passed over a time through the wire section. To find the magnitude of small electricity, milliammeters, microammeters and galvanometers are used, which are also connected to the place in the chain where the current is required. Connection can occur in two ways: sequentially and parallel.

The determination of the strength of the current consumed is not so often in demand as measuring the resistance or voltage, but without finding the physical value of the strength of the current is not possible to calculate the power consumption.