The direction of the current in the first two series circuits urgent!!!!!

Start by drawing the simplest parallel circuit on paper. (When you asked a question, you were talking about a series circuit, but from your question, I found that it was a parallel connection.) "In a series circuit, it's time for a fork. "It's all at a fork in the road, where else is it in series? )

The first situation that your teacher said, that is called a short circuit, in layman's terms, I am the current, I see that there is a fork in front, there are electrical appliances on one road to use me, to consume me, the other road is flat, of course I have to choose a flat road! As for whether you have to go to the road with useful electrical appliances first, and then find out that there are useful electrical appliances on this road, and then divide the troops into another road, and find out that this road is unimpeded, so you make a decision to take the smooth road, and it is normal for beginners to have this kind of idea! But don't be held back by such doubts, everything is instantaneous, don't think too much!

In the second case that your teacher said, I told you that you know the formula of the parallel circuit, except for the short circuit, the voltage on the parallel branch line (the bifurcation you said) of the parallel circuit is equal. And the voltage is equal to the current * resistance, I will make an analogy: I am the current, I see that there is a fork in front, there is a small bulb on one road, there are two small bulbs on the other road, the resistance of the two small bulbs is greater than the resistance of a small bulb, according to the formula of parallel circuit:

The voltage is equal to the current * resistance, and the voltage on each fork is equal, then the current on the channel with the small resistance is greater than the other channel.

So, in general, it should be said that the current passing through the least electrical side of the parallel circuit is the largest, but it is not only passing through here! The teacher said it wrong. (There is a relativity here, if the resistance difference between the electrical appliances on the two roads is large enough, it can be regarded as a short circuit, but it is indeed only from the least electrical side, but the premise is that the resistance difference is extremely large).

If there is an electrical appliance on one side and no electrical appliance on the other road, all the current will pass through the side where the appliance is not used.

At this time, it is a short circuit, because on the side where there is no electrical appliance, there is no resistance, there is no resistance, so of course the current has to go from this side.

The current will pass through the least used electrical appliances.

Because the resistance of this circuit is small, the resistance is small, so the current goes from this side, for example, there is a rabbit on one road, and a tiger on the other road, which one will you choose? Of course, there is the one with rabbits.

Does he mean that when you fork the road, you have to try which road has the least electricity before deciding which way to take???

No, the charge is not like flowing water, one goes, the next one goes on, but flows at the same time, stops at the same time, so they don't try, because the resistance on this branch will affect the whole branch, at the fork, the charge can sense the size of the resistance, so you can judge the amount of electrical appliances.

Also, to judge the number of electrical appliances, do you start from the positive pole of the battery and count the number of electrical appliances in the process of returning to the negative electrode???

Yes. If there are 2 appliances on one branch and 1 on the other, then the current may go from the branch of the 1 appliance, that is, the current only goes through the road with the least appliances.

This is to look at the resistance. To use an analogy: there are two paths in front of you that lead to your school; The distance is the same; But on one of the roads, there is a teacher at every moment that you are very annoyed with; So which way will you go?

Similarly; On the parallel circuit, there is a road with electrical appliances; If there will be resistance, then bypass! But if there is a teacher on both roads that you are very annoyed by, then both roads are about the same, so you can go, in the same way, there are electrical appliances on both roads, then the current on both roads can choose to go, so there are currents.

First of all, the current eventually forms a loop, which is what you said about starting from the positive electrode to the negative electrode. Therefore, it is not possible to go from positive to positive. You can see the flow clearly, and without electrical appliances, it can't form a circuit.

The main problem about the number of electrical appliances is that the voltage is not enough, and it is easy to pass the current with a low voltage because it is a series connection.

In a parallel circuit, if one wire has a resistance of 0, then the current of the other wire is 0In reality, there is no line with a resistance of 0, so no matter how much resistance the other line has, he always has current, but the current passing through it is negligible, it is not that there is no current, so we think that he has no current, and that is wrong!

In parallel, the voltage at both ends of the 2 lines is equal, voltage = resistance current, and you can think about the rest, hehe!

It depends on how much resistance there is.

It usually goes through a small resistor.

Use the ammeter to test the two circuits to see which one has the current pass ratio.

The law of current in a series circuit.

Inflow from the positive electrode and outflow from the negative electrode'

Experimental equipment: power supply, two small bulbs, one switch, several wires Experimental procedure:

Ask the question] What is the relationship between the trunk current and the current of each branch in the parallel circuit [Conjecture and hypothesis] The trunk current in the parallel circuit is equal to the sum of the currents of each branch [Design and carry out experiments] Connect the ammeter to point A, point B, and point C in the circuit respectively, measure the current, and see what relationship there is between them Replace the other two small bulbs and measure again to see if there is still the same relationship Record the results of the three measurements in **

Conclusion] The dry circuit current in the parallel circuit is equal to the sum of the branch currents

1. Draw a simple circuit diagram of series resistance.

2. Measure the current of the entire series part.

3. Measure the current at both ends of each resistor separately.

4. Compare the relationship between currents and draw conclusions.

Specifically, it's OK to add the resistor R1, R2 or something.

Series current current current law: In series circuit, the current is equal everywhere Series circuit voltage law: The total voltage at both ends of the series circuit is equal to the sum of the voltages at both ends of each part of the circuit, that is, u=u1+u2+....

Parallel circuit voltage law: In parallel circuit, the voltage at both ends of each branch is equal to the voltage at both ends of the trunk circuit The parallel circuit current law: the total current in the trunk circuit is equal to the sum of the currents in each branch, that is, i=i1+i2+....

So the answer is: equal, u=u1+u2+...., equal, i=i1+i2+....

The law of current in a series circuit.

The currents are equal everywhere in series.

The sum of the parallel connections is equal to the total current.

The current of the series circuit is equal everywhere, that is, I total = i1 = i2 = i3 --- = in, and the total voltage is equal to the sum of the voltages at both ends of each electrical appliance, that is, u total = u1 + u2 + u3 --- un

In parallel circuits, the voltages are all equal, that is, the total current of u = u1 = u2 = u3 = --- = un is equal to the sum of the currents of each branch, that is, i total = i1 + i2 + i3 + --in

Current definition: The algebraic sum of the number of charges passing through a section per unit time.

When the circuit is stable, when L1 and L2 are connected in series, the sum of the number of charges passing through their respective sections per unit time is equal, so the current flowing through the two inductive elements is equal.

Since the greater the reactance of the inductor, the greater the effect on the charge passing through the barrier. In order to ensure that the number of charges passing through the unit time is equal, the potential difference between the two ends is greater. The potential difference is expressed in voltage.

Therefore, the current of the series circuit is equal and the voltage is proportional to the reactance.

According to Ohm's law: u=i*r. When the current i is the same, but the resistance values of l1 and l2 are different, the voltage u is different.

Questions about the current:

According to Kirchhoff's first law, the current flowing into the node is equal to the current flowing out of the node, and since L1 is connected in series with L2, there are only two branches on the connecting node, so the currents of L1 and L2 are equal.

Figuratively speaking, the two pipes connected together, the water flowing in and the water flowing out is the same, and it has nothing to do with the length of the pipe, do you understand?

And what is the difference between the current in a series circuit and a parallel circuit?

The following formula must be memorized, and the exam must come.

Current. The defining formula is i=q t

Ohm's law i = u r

Series circuit i=i1=i2

Parallel combustion chain bucket combustion circuit i=i1+i2

Voltage. Series circuit u=u1+u2

Parallel circuit u=u1=u2

Resistance. Total series r = r1 + r2

Total parallel r = r1r2 (r1+r2).

i=u/ru=ir

r=u/ip=w/t

p=uip=u^/r

p=i^rq=uit

q=u^/rt

q=i^rt

Tandem: i total = i1 = i2 = ==

u=u1+u2+++

p total = p1 = p2 +++

Total w = w1 + w2 + + +

u1 u2=r1 pico-pin sun r2

r total = r1 + r 2 + + +

Parallel: i total = i1 + i2 + + +

u=u1=u2===

p total = p1 = p2 +++

1 r total = 1 r1 + 1 r2+++

Total w = w1 + w2 + + +

Ohm's law i = u r

Joule's law: q = i 2rt

Deformation formula: q=uit

q=u^/rt

ps：w=pt

In a series circuit, the current is equal everywhere i, total = i(1) = i(2) = ....i(n)

Ohm's law The voltage must be the same resistance, then the current is the same: i=u r

Otherwise, the excess current will flow to **.

Why is the flow of water in one of the pipes in the house equal, if not, it must be a leaking pipe.

Microscopically speaking, the current is actually the outermost electron of the metal element flowing under the action of voltage (electric field force) due to instability, which is the opposite direction of the so-called current in reality. According to what conservation law, electrons do not arise and disappear out of thin air, so the number of electrons flowing into a circuit must flow out of the same number of electrons, and the definition of electric current is the charge passing through a certain cross-section of a conductor per unit time.

Current characteristics in series circuits: The currents in series circuits are equal everywhere

So the answer is: equal

If this unknown resistance is close to infinity, then 2 ohms is almost negligible with respect to infinity, then we consider that the resistance has hardly changed, and the current is almost constant, which is of course practically unacceptable).

If the resistance tends to 0, then the voltage is almost, and if it is 10 ohms, the current is of course actually unacceptable).

Everything else is in between.