How to judge the series and parallel connection of the circuit, how to judge the series circuit and

There are many ways to do this, but there are two simpler ones.

The first is the current method: if there is only one path of the current, it is connected in series, and if the current flows out and there is a branch, then it is connected in parallel.

The second is the component removal method: in the series circuit, each electrical appliance affects each other, one can not work normally, and then affects other electrical appliances, in the parallel circuit, each electrical appliance does not affect each other, one can not work normally, does not affect other electrical appliances.

The most important point is to be able to accurately determine the direction of the current, and some branches may have zero current, which must be noted. Only first judge the flow direction of the current, and then you want to judge whether some branches or elements are connected in series or in parallel, then just select the two ends of each branch or original, and see whether the corresponding two endpoints are directly connected together through the wire, which is parallel, if not, it may be series or series-parallel mixing. Hope it helps.

The electrical appliances are connected in series from end to end; The head and tail of the electrical appliances are pinched together, and they are connected in parallel with the power supply.

Hope mine is helpful to you

You can choose.

Think of the circuit as if it were a road.

And then you walk down this road.

Use a pencil to draw the trajectory you are taking.

If you're completely down one path, then it's tandem.

If you're walking at an intersection then it's in parallel.

The problem is generally combined in series and parallel.

Looking at the direction of the current, before reaching the electrical appliance, if there is a road, it will go to the next electrical appliance, it is a series connection; If there are more than two moves, it is in parallel.

Hope you understand.

Xueba tells you that if it is shunted, it will be parallel.

JudgmentSeries circuitsand the parallel circuit method is as follows:

1. Fulcrum method: the circuit without the fulcrum must be a series circuit, but the circuit with a fulcrum is not necessarily a parallel circuit. This method can only determine that it is a series circuit when there is no fulcrum, and if there is a fulcrum, the following methods are required for further identification.

2. Path method: In the process of moving from the positive pole of the power supply to the negative pole of the power supply, if there is only one path, it is a series circuit, and if there are multiple paths, it is a parallel circuit.

3. Demolition method: If after removing an electrical appliance, the other electrical appliance cannot work normally, it means that the two electrical appliances are connected in series, and if the removal of one electrical appliance has no effect on the other electrical appliance, it means that the two electrical appliances are connected in parallel.

Fourth, from the series and parallel circuits of the respective characteristics to identify:

1. Parallel circuit:

1) The circuit has several paths.

2) The trunk switch controls all the electrical appliances, and the branch switch controls the electrical appliances of the branch.

3) The electrical appliances have no influence on each other.

2. Series circuit: In the series circuit, the current is equal everywhere. In parallel circuits, the voltages are equal everywhere. The electrical appliances of the series circuit are connected in the circuit from end to end, and the circuit has only one path, and any open circuit will be broken.

5. Series circuit: The total voltage of the series circuit is equal to the sum of the voltages at both ends of each part of the circuit.

6. Parallel circuit: The voltage at both ends of each branch in the parallel circuit is equal. and equal to the total voltage. In parallel circuits, regardless of the change in the resistance of each branch (sliding rheostat. , all of which will not affect the voltage. Voltmeter.

v Meter Volts) in parallel: The voltage value measured anywhere in the parallel circuit is the same.

Method for judging the series and parallel connection of circuits:

1. Use the definition method to identify series-parallel circuits.

If the components in the circuit are connected one by one, the circuit is a series circuit, and if the components are connected in parallel between two points of the circuit, the circuit is a parallel circuit.

2. Use the current flow direction method to identify series-parallel circuits.

Starting from the positive (or negative) pole of the power supply, the path through which the current flows is analyzed along the direction of the current. If there is only one path through all the consumers, the circuit is connected in series; If the currents branch in one place and converge at another, the circuits between the branches and the confluence are parallel.

The current flow direction method is a commonly used method in circuit analysis.

3. Use the node method to identify series-parallel circuits.

Node method: In the process of identifying the circuit, no matter how long the wire is, as long as there is no power supply, electrical appliances, etc., the two ends of the wire can be regarded as the same point, so as to find out the common points at both ends of each electrical appliance. The "node method" is mainly used for the identification of non-standard complex circuits, which has certain difficulties.

If there are three consumers in the circuit and only two current paths, then there will be one consumer on the main road, or two consumers connected in series on a branch road, and the circuit must be mixed.

4. Use the removal method to identify the series-parallel circuit.

The demolition method is an important method for identifying difficult circuits. Its principle is that the electrical appliances in the series circuit affect each other, and if any electrical appliance is removed, there will be no current in the other electrical appliances; In the parallel circuit, each electrical appliance works independently and does not affect each other, and removing any one or several electrical appliances will not affect other electrical appliances.

The first trick: the current flow method (or the path method)!

When the current starts from the positive pole of the power supply, the circuit will have the first shunt, one flows into the bulb L1, the other flows into the bulb L2L3, and the flow is split again between the bulb L2L3, one flows into the bulb L2, and the other flows into the bulb L3, so obviously, the current is divided into three branches after starting from the positive pole of the power supply, they enter the three bulbs respectively, and then after passing through L1L2, they form a branch and merge again with a branch through the lamp L3 and return to the negative pole of the power supply. It can be seen from this that the three bulbs are three independent branches, so they are connected in parallel.

The second trick: the wire stretching method.

When we study electricity, physics teachers should emphasize one point, that is, the wire can be arbitrarily elongated or shortened, can be regarded as a point, or can be arbitrarily bent and connected. This gives us a revelation, we might as well think of the straight line in the schematic diagram as a wire that can be bent at will in life, so we can stretch the wire in the circuit. In the following three figures, when the first and last of the three bulbs are connected, we can see at a glance that the three bulbs are connected in parallel.

The third trick: the demolition method.

Because the parallel circuits are independent of each other and have no influence, the electrical appliances of the series circuits are all affected by each other. Therefore, we can use the "removal method" to determine the series-parallel connection problem of the circuit. We can remove any one of the three bulbs, as shown in the image below, and we can see that when we remove any one of the bulbs, the other bulbs can still form a pathway!

In other words, the three bulbs do not affect each other, so it can be concluded that the three bulbs are connected in parallel!

1 6 Step by Step Reading.

First of all, use a pen to connect to the power supply through the wires at the left and right ends of the series circuit electrical appliances.

2 6 Secondly, use a pen to connect the left and right ends of the electrical appliances in the parallel circuit, and connect them to the power supply through the wires respectively.

3 6 After depiction, it was found that the series circuit could not be connected to the power supply with both ends of the electrical appliance.

4 6 The parallel circuit can be connected to the power supply by the left and right ends of the electrical appliance through the wire.

5 6 Then use the same method to depict a complex circuit diagram: connect the left and right ends of the electrical appliances in the circuit to the power supply through the wires.

6 6 From the process depicted by the red line, it can be seen that L1 is connected in parallel with L2, L3, and L4, and L4 is connected in series with L2 and L3.

To determine whether a circuit is connected in series or parallel, it can be judged according to the distribution of current and voltage.

If all the electrical components in the circuit are connected in the same path, and the currents on any of the components are equal until the age is equal, then the circuit is a series circuit. If the components in the circuit are connected in different paths, and the voltage is equal on any of the components, then the circuit is a parallel circuit.

The key to determining whether a circuit is connected in series or parallel is to understand the distribution of current and voltage in the circuit. In a series circuit, electrical components are sequentially connected in the same path, forming a closed loop. As a result, current can only flow along this path, and the magnitude of the current is equal on any one element in the series circuit.

This is because there is only one path to choose from, so the magnitude of the current does not change depending on the path. In contrast, in a parallel circuit, the electrical components are connected in different paths, and these paths are connected to the positive and negative poles of the power supply. In parallel circuits, current can be shunted in different paths into the individual electrical components.

Because the components in a parallel circuit can be connected along different paths, the current can be distributed between the components and eventually returned to the negative end of the power supply. In parallel circuits, the magnitude of the current on the individual components can be different. By understanding and applying these principles, we can determine how a circuit is connected.

In practice, the components in a circuit are often complex and consist of multiple electronic components.

Characteristics and applications of series and parallel circuits

Both series and parallel circuits are common connections in circuits, and they have different characteristics and applications. Series circuits are characterized by equal currents and unequal voltages. Since there is only one path for the current to flow in a series circuit, the magnitude of the current is equal in the series circuit.

However, due to the different impedances or resistances of electrical components, the voltage is distributed between the individual components.

Therefore, the voltage of the series circuit can be calculated according to the way the resistance is distributed. Parallel circuits are characterized by equal voltages and unequal currents. In parallel circuits, current can be shunted in different paths to the individual electrical components.

In this way, the voltages of the individual components in the parallel circuit are equal because they are all connected to the positive and negative poles of the power supply. And because the impedance or resistance of the electrical components is different, the current will be distributed between the different components.

1.If it is a DC voltage source, the characteristics of capacitor series voltage division can be introduced according to the middle school physics

1) The total voltage at both ends of the capacitor series circuit is equal to the sum of the voltage division at both ends of each capacitor. i.e. u=u1+u2+u3+....＋un。

2) When the capacitors are connected in series, the voltage distributed on each capacitor is inversely proportional to its capacitance. i.e. un=q cn (Because in a capacitor series circuit, the amount of charge on each capacitor is equal, the higher the capacitance, the lower the voltage distributed by the capacitor, and the lower the capacitance, the higher the voltage distributed. ）

Then the voltage source of 4V, and the voltages on the two capacitors of 1F are 8 3V and 4 3V respectively

2.If it is an AC voltage source, the impedance of the capacitor is xc = 1 j cxc|Inversely proportional to c, will |xc|The same result can be obtained when the voltage division is calculated as a resistor.

Extended information: Series connection is one of the basic ways to connect circuit components. Circuit components (such as resistors, capacitors, inductors, electrical appliances, etc.) are connected or stoveed one by one.

The circuit composed of connecting various electrical appliances in series is called a series circuit. In a series circuit, the current through each consumer is equal.

Main features: Two or more components are arranged in a string, and the first end of each component and the tail end of the previous component are connected into a node, and this node is no longer connected with other nodes. The diagram shows three components in series.

the first end of the element 3 and the end end of the element 2 are connected to form a node q; The root end of element 2 and the tail end of element 1 are connected to form node p. The first end A of Element 1 and the last end B of Component 3 are connected to the other nodes of the circuit, respectively.

The main characteristics of series circuits are:

The current in all series elements is the same current, i total = l1 = l2 = l3 = ......ln。

The total voltage of the components in series is the sum of the terminal voltages of all the components, u total = u1 + u2 + u3 + ......un。

In the circuit illustrated, u is the total voltage, and u1, u2, and u3 are the voltages of the components, u=u1+u2+u3.

The method of judging whether the appliances in a circuit are connected in series or in parallel:

Series and parallel connection are the two most basic forms of circuit connection, and there are certain differences between them. To determine whether the components in a circuit are connected in series or parallel, it is necessary to grasp their basic characteristics, and the specific methods are:

1) Electrical connection method: analyze the connection method of electrical appliances in the circuit, and connect them in series one by one; Parallel between two points in a circuit is parallel.

2) Current flow direction method: when the current flows out of the positive terminal of the power supply, it flows through each component in series in turn; When two branches flow separately in a shirt and finally merge together, it indicates that the circuit is connected in parallel.

3) Removal of component method: arbitrarily remove an electrical appliance to see whether other electrical appliances are working normally, if all electrical appliances have been removed, and other electrical appliances can continue to work, then the connection relationship of these electrical appliances is parallel; Otherwise, it is tandem.