Current stationary electrical worker
1) Conductor :
A conductor is means in which there are many free electrons to move between the reticular plans.
2) Current electrical worker and its unit of measure:
The current electrical worker is the amount of loads that
section of the circuit in the time unit flows through one, 
measure in Ampere.
3) stationary Current :
Current is one whose value is constant in the time.
4) medium free Way :
The medium free way is the medium way covered from an electron between a collision and the successive one with the Ionian ones of the crystalline reticulum.
5) Density of J current :
J = nqvD
n = number of bearers to volume unit
q = it loads with the bearer
vD = speed of drift or speed that is come to establish as consequence of hits, the motion would have to be accelerated but therefore like for the viscous fluid it is come to establish the maximum speed that the bearer can assume between two hits happened to you. VD forms a vectorial field with equal direction to that one of and and towards dependent from the polarity of it loads with the bearers, in module is worth approximately 2,3 * 10-5 .
6) Relation between and the J :
The current that it crosses a S section of the conductor
is equal to the flow of J through S
7) Relation between J and and :
being s the
conductivity electrical worker, the inverse one of the resistività.
8) Equation of continuity of the current :
9) Node :
Approximately punctiform zone in which they converge varies covered thin conductors from current.
10) Branch :
Logon directed between 2 nodes, covered from a specific current.
11) Mesh :
With of coppers that one forms line comprising sluice others nodes.
12) 1ª law of Kirchoff (for the nodes) :
In stationary conditions the algebrica sum of the currents entering and outgoing in a node is equal to zero. It derives from the fact that the flow of J through the sidewalls of a streamtube is null.
13) 2ª law of Kirchoff (for the meshes) :
On every mesh of a circuit, in stationary conditions, the
algebrica sum of the potential differences is null them between the
ends of the various coppers that constitute the mesh same 
. Drift from the conservatività of ands .
14) Law of Ohm :
V = RIVERS
15) Resistance and conductance and unit of measure :
The resistance is a measure of the opposition offered from the material to the current passage, it is due exactly to hits of the bearers against the Ionian ones of the reticular plans, measure in Ohm W , the G conductance is to the contrary a measure of the facility with which the bearers they cover the conductor measure in Siemens.
16) 2ª law empiricist of Ohm :
Being r the resistività electrical worker of the material.
17) Law of Ohm in instantaneous shape :
It is obtained replacing 2ª the law of Ohm in the 1ª and observing that V/l = E e I/S = J.
18) Course of the resistività r with the centigrade temperature:
19) Joule Effect and its law :
The numerous ones hit of the bearers against Ionian of the
crystalline reticulum the damage place to a power that comes dispersed
under heat shape, W = Rthe 2 .
in local shape 
obtained based on
considerations on the infinitesimal job.
20) elettrogeneratori or Generators f.e.m. :
They are able devices to maintain a potential difference to you them constant to the heads of a conductor covered from current.
21) electromotive Field :
The electromotive field is what it is settled down to the inside of the generator and that works in opposite direction to the present electrostatic field to the clips, it is not conservativo. It in short separates to the charges pushing positive towards the positive clip and the those negatives towards the clip negative.
22) Electromotive force and its unit of measure :
It is the job completed from the generator in order to
move loads positive unitarian from the clip negative to the positive
clip. 
, measure in Volt.
23) operating Definition of f.e.m. :
The f.e.m. it is the potential difference them that measure to the heads of the generator to opened circuit, to the equilibrium it is had in fact that the electromotive field is equal and opposite to the electrostatic field.
24) controelettromotore Field and back electromotive force:
It is a field localized on not ohmic cargos of use, it
absorbs energy to the bearers and therefore it is opposed to the
electromotive field. 
.
25) Relation between ability and resistance in a condenser with dielectric in loss :
RC = r and
26) Law of generalized Ohm :
It is obtained from the
considering andand, andS , andCE .
27) 2ª law of Kirchoff (for the meshes) :
being the number of the branch pertaining to the
mesh.
28) Number of independent meshes in a circuit :
Independent meshes = Coppers - Nodes 1
29) Parallel of 2 generators :
One obtains the equivalent of an only generator with inner resistance halved and the same one fem.
30) Method of Cramer for the calculation of the single current :
to) the equations of the meshes are written isolating the currents to 1° the member and to according to member they are put upgrades them.
b) the relationship of 2 determining ones adopts a position
Num : famous terms in place of the coefficients of the incognito current
Den : coefficients of the 3 incognito currents.
31) Theorem of superimposition :
The current that passes in a branch of a net can be expressed like sum of the currents that would circulate if every f.e.m. it operated singularly.
32) Theorem of Thevenin:
A circuit can be replaced from the equivalent resistance and the equivalent generator that look at the heads of 2 its clips. The equivalent resistance gains cortocircuitando all the generators and calculating series and parallels, the generator equivalent instead seeing the potential difference them that user is introduced to the heads of the circuit in absence of the net.
33) Condition of maximum power transferred to the cargo :
The maximum transfer of power between circuit and cargo in the case of adaptation of stiffness is had that is when the resistance equivalent of the circuit is equal to the resistance of the cargo.
34) volumica Density of loads in the stationary case:
rC = 0 as it is
obtained replacing the law of Ohm in local shape in 1ª the equation
of Maxwell and remembering that and
therefore being in the stationary case 
.
Therefore the charges are offered on the surface of the
conductor.
35) Value of the inner electric field to the conductor :
It is directed along the axis of the same one and is worth 
.
36) Distribution of the charges in the conductor :
The positive ones get thicker towards the positive electrode and the negatives towards the electrode negative.
37) nearly stationary Conditions :
The sollicitations electrical workers vary in the time, but with clearly inferior speed to the speed with which it marks them propagano in the circuit.