What is the relationship between trunk and branch currents in physics?

When the circuit insulation is damaged due to a cause, including overload, and the conductor with unequal potential is turned on at a fault point with negligible impedance, this is called a short circuit. Because the path of this short-circuit circuit is all metal path, this short-circuit is classified as a metallic short-circuit, and its short-circuit current value can reach hundreds to thousands of times of the current carrying capacity of the circuit conductor, and it can produce abnormal high temperature or huge mechanical stress to cause disasters. In order to make the overload protection electrical appliance protect the circuit from overload, the protective electrical appliance and the protected circuit should cooperate with each other in some parameters, and they should meet the following conditions:

1) The rated current or setting current i of the protective appliance shall not be less than the calculated load current i of the circuit. (2) The rated current or setting current i of the protective appliance shall not be greater than the allowable continuous current carrying capacity of the circuit (hereinafter referred to as the current carrying capacity). (3) Guarantee prevention....

To put it simply, a complete circuit can have no branches, but it must be a trunk circuit, for example, the branch current is a lot of streams, and these streams will eventually converge into a big river, and this big river is the trunk current!

The total current of the trunk current is equal to the branch current. But only if it's a purely resistive network. If there is a nonlinear element such as an inductor....That's not the case.

Based on the conservation of charge, the algebraic sum of all path currents for each node is zero. In a pure resistive circuit, the dry circuit is equal to the sum of the currents of all the branches.

The trunk current is equal to the branch current. Complete!

According to KCL: i1 = i2 + i3.

According to kvl: 1 i1 + 20i2 + 30i2 = 26;

1×i1+10×i3+40i3=26。

Solution: i1=1, i2=i3=.

1) The number of branch currents to be sought is determined by the number of branches m of the circuit. circuits.

m=6, then the branch current has i1

i2….i6i6 six.

2) The number of nodes n=4, and n-1 independent node equations can be listed.

3) List the loop equation according to KVL.

Select l=m-(n-1).

independent loops, the winding direction is selected, and the equations for l independent loops are listed by KVL.

i1r1+i2r2+i4r4=us1。

i3r3-i4r4-i5r5=-us2。

i2r2-i3r3+i6r6=0。

Extended information: The branch current method lists the required equations for junctions and loops by applying Kirchhoff's current law and voltage law, respectively, and then solves for each unknown branch current.

It is the most direct and intuitive method of calculating complex circuits, and the premise is to select the reference direction of the current

The branch current analysis method uses the current of each branch in the circuit as an unknown quantity, directly applies KCL and KVL to list the equation of the branch current, and then solves the branch current from the listed equation.

Hello dear, happy to answer your <>

In AC circuits, there is a relationship between the trunk current and the branch current. The trunk current refers to the main current of the circuit, while the branch current refers to the current in the various branches that branch out from the trunk circuit. According to Kirchhoff's current law (kcl), at any one node, the current flowing into the node is equal to the current flowing out of the node.

This means that the dry answer current is equal to the algebraic sum of all the line impulse companion branch currents. In other words, the trunk current is a vector synthesis of the branch current. For example, if an AC circuit has one power supply followed by two branches connected in parallel, the trunk current will be equal to the sum of the two branch currents according to the KCL.

i.e., i trunk = i leg 1 + i leg 2. Also, in an AC circuit, the magnitude and phase of the current are interrelated. The sum of the branch currents determines the magnitude of the trunk current, and components such as resistance, inductance, and capacitance in the branch will affect the phase of the branch current.

Therefore, when analyzing AC circuits, it is necessary to consider the phase difference of the branch current and its effect on the dry circuit current.

Hello! In an AC circuit, there is a certain relationship between the trunk current and the branch. The trunk current refers to the main current flow path in the circuit, while the branch circuit is the branch circuit outside the trunk circuit.

According to Kirchhoff's law of current, in an AC circuit, the trunk current is equal to the algebraic sum of the branch currents. Specifically, if there are multiple branches in a circuit, and the current direction of each branch can be positive or negative, then the dry current is equal to the algebraic sum of the currents of the individual branches. For example, if there are two branches in a circuit, one of which has a current of 2A and the other has a current of -1A, then the trunk current is 2A + 1A) = 1A.

This relationship can be applied to a variety of circuits, including series circuits, parallel circuits, complex network circuits, etc. By calculating the branch current, we can obtain the value of the dry circuit current, which can better understand the current distribution in the AC circuit. In addition to Kirchhoff's current law, Kirchhoff's voltage law is also an important method for solving AC circuit problems.

Kirchhoff's law of voltage modes states that in a closed loop, the sum of the voltages of the individual voltage sources and resistive elements is equal to zero. By applying these two laws, we can solve various complex AC circuit problems, analyze the distribution of voltage and current, and calculate the resistance and power of the power supply. Hope the above helps!

Summary. In AC circuits, there is a certain relationship between the trunk current and the branch. Trunk current refers to the main current in a circuit that is directly connected to the power supply, while a branch refers to other current paths that branch off from the trunk.

In the first-flow circuit, there is a certain relationship between the current of the trunk circuit and the branch before the core. Trunk current refers to the main current in a circuit that is directly connected to the power supply, while a branch refers to other current paths that branch off from the trunk.

According to Kirchhoff's law and Ohm's law, the following relationship can be derived:

1.The trunk current is equal to the algebraic sum of all the branch currents. According to Kirchhoff's law, the current is conserved at the node, i.e., the total current is equal to the total <>current of the collision leaving the node

Therefore, the trunk current is equal to the sum of the currents passing through the branch.

2.The distribution of the parallel trace current depends on the resistance or impedance of the branch. According to Ohm's law, current is equal to voltage divided by resistance or impedance. Therefore, the spike current of the branch depends on the magnitude of the resistance or impedance of the branch.

3.The rubber-liter of the branch current can be distributed by the series resistance or the proportional series impedance. In a series circuit, the current is distributed proportionally between the individual series elements, inversely proportional to their resistance or impedance. A branch with a lower resistance beam or impedance than the town will be subjected to a greater current.

In addition, there are complex phase relationships in AC circuits, which can cause phase differences in the time of the branch currents. Therefore, when analyzing the AC circuit, in addition to considering the size of the current, it is also necessary to consider the phase difference of the current.

In short, there is a relationship between Kirchhoff's law and Ohm's law between the trunk current and the branch in the AC circuit, where the branch current depends on the resistance or impedance of the branch.

According to KCL: i1 = i2 + i3.

According to kvl: 1 i1 + 20i2 + 30i2 = 26;

1×i1+10×i3+40i3=26。

Solution: i1=1, i2=i3=.

1) The number of branch currents to be sought is determined by the number of branches m of the circuit. The circuit m=6 , then the branch current has i1 , i2 ...i6i6 six.

2) The number of nodes n=4, and n-1 independent node equations can be listed.

3) List the loop equation according to KVL.

Select l=m-(n-1) independent loops, select the winding direction, and list the equations for l independent loops by kvl.

i1r1+i2r2+i4r4=us1。

i3r3-i4r4-i5r5=-us2。

i2r2-i3r3+i6r6=0。

Three kvl equations: and three kcl equations: each equation can be solved for a branch current.

As shown in the figure, i3, i4 and i5 can be obtained by calculating the difference of mesh current. This problem can use the mesh current method to calculate i1, i2, and i6 in the diagram, and the column formula is as follows:

2+4)i1-2i2-4i6+12=0

2i2-2i1+14-8=0

5+4)i6-4i1-14-6=0

The answer is obtained by calculating the above three formulas:

i1=，i2=，i6=。

In the calculation of i3, i4, i5 get the answer:

i3=i2-i1=-3（a）。

i4=i6-i2=。

i5=i6-i1=。

i3=(8-14)/2=。The same is done in the same way.

One of the most basic theorems of the branch current method is that the current on the same branch is equal.

If you look at this theorem, you can see that the two new currents I4 and I5 that you marked on the diagram are actually the same branch of I4 and I1 (the branch that flows through the 20V voltage source), and I5 and I3 are the same branch (the rightmost branch).

Then: i1+ i3 = i2 (1);

i1*(15ω+5ω) i2*20ω = 20v (2);

i2*20ω=-i3*(20ω +30ω +10ω）+86v - 6v (3)

3) Eq. : i2 = 4 - 3 * i3 --1) --- i1 + 4 * i3 = 4

i1=0a, i2=1a, i3=1a