Does the current distribution in a parallel circuit change with the magnitude of the resistance?

Yes, Ohm's law current = voltage ratio resistance. In parallel circuits, the voltages are equal everywhere, and if the current of the branch is larger, the resistance is smaller. r1/r2=i2/i1

Definitely, the voltage in a parallel circuit does not change, and there is Ohm's law i=u r, and the current will definitely become.

Total resistance variable.

It's small. Parallel circuit, source at both ends.

The voltage is equal, the current at both ends is the sum of the current of each electrical appliance, the parallel circuit is equivalent to one electrical appliance, then r=u i where i=i1+i2,i1=u r1,i2=u r2, so i=u r1+u r2=u(r1+r2) r1r2 so the equivalent resistance r=u i=r1r2 (r1+r2) r1 r=(r1+r2) r2>1, in the same way, r2 r>1, so r is less than any of the sub-resistors.

Total resistance variable.

Copy the total electric du according to the shunt resistance

Relationship between resistance and partial resistance:

1/r=1/r1+1/r2

rtotal = r1r2 (r1+r2) = r1 (1+r1 r2)r total = r1r2 (r1+r2)=r2 (1+r2 12) The total resistance of a parallel circuit is higher than that of each DAO

The resistance of each resistor is small.

If you simply increase the resistance of one sub-resistor, then the total resistance increases. If a new resistor is added to the parallel circuit, the resistance equivalent to the original resistance value of positive infinity becomes a resistance value of r, and the total resistance naturally decreases.

1. It's smaller.

2. Reason: and bai joint is equivalent to adding.

The larger the cross-sectional area of the wire, the smaller the resistance.

3，1/r=1/r1+1/r2

It can also be proved mathematically.

There is only one resistor in the circuit: r total = r1

If R1R2 is connected in parallel in the circuit, then R will always be smaller than any resistor.

If you increase the resistance by one sub-resistance, the total resistance will also increase. Composed.

Any increase in the partial resistance will cause its reciprocal to decrease, and finally the reciprocal of the total resistance will also decrease, and the decrease in the reciprocal is the increase of the denominator, that is, the increase of r.

The total current in a parallel circuit is equal to the sum of the currents on the resistors in each branch circuit. i=i1+i2。

Parallel connection is a connection mode between components, which is characterized by connecting two components and devices of the same or different classes, and at the same time, the tail and tail are also connected. It is usually used to refer to the way in which the electronic components in a circuit are connected, that is, parallel circuits.

Analysis & Process:

The characteristics of parallel circuits are: the voltage is equal everywhere, that is, the voltage and total voltage of each branch are equal.

So: according to Ohm's law: i = u r

When the voltage is constant, the current is inversely proportional to the resistance.

So: the current distribution of the parallel circuit is inversely proportional to the resistance.

Because it is connected in parallel, the voltage does not change, so according to Ohm's law, the greater the resistance, the smaller the current, and the lower the resistance, the larger the current. So it's inversely proportional.

In Ohm's law, current = voltage resistance, whether it is in parallel or series, calculate the resistance value first, and everything is clear.

This is explained in two cases, as shown in the figure below

Figure 1: As the resistance of R1 increases, the current of R1 decreases while the current of R2 remains unchanged because the voltage at both ends of R1 and R2 is constant.

Fig. 2 R1 resistance increases, the equivalent resistance of R1 and R2 parallel circuits increases, the voltage V12 at both ends increases, V2 decreases, the current of R2 increases, and the current of R1 needs to be calculated (V12 R1). [It seems that the current of R1 is going to decrease, but the voltage of V12 is increasing, so it needs to be calculated].

Assuming that the power supply is regulated, then the voltage of the resistor does not change, the current flowing through it becomes smaller, and the voltage and current of the other resistor remain the same.

If there are two resistors in the parallel circuit, the resistance value of one resistor becomes larger, and the total resistance should also be increased accordingly, such as the power supplyNot an ideal voltage sourceThen the voltage at both ends of the resistor increases, and the current of the resistor becomes smaller and the current of the other resistor increases. Such as power supplyIt is an ideal voltage sourceThen the voltage at both ends of the resistor does not change, and the current of the other resistor decreases by increasing the resistance.

In the case of junior high school physics, the resistance becomes larger and the current becomes smaller when the power supply voltage remains the same; Because the parallel connection does not affect each other, the other resistance does not change!

Suppose there are two resistors, R1 and R2, when the R1 resistance becomes larger, the voltage on both ends of it does not change, and the current flowing through it decreases. The voltage and current of R2 do not change.

First, make sure that the supply voltage is fixed, then ignore the resistance of the wire, and then make it clear which object the voltage, current, and resistance are all aimed at in your question.

1.In parallel circuits, the resistance changes, the voltage of course does not change, the voltage is a fixed value, and the change is the current.

2.In a series circuit, the resistance of a certain part increases, the voltage at both ends of the corresponding part increases, the total current of the circuit decreases, and the total voltage remains unchanged.

3.A small current and a small voltage are not necessarily small because the resistance can be large; In the same way, if the current is large, the voltage is not necessarily large, and the resistance may be small.

4.Regardless of whether the circuit is connected in series or parallel, the relationship between the three is U=IR, that is, the voltage is equal to the current multiplied by the resistance. The only difference is that the resistance of parallel circuits is calculated differently than those connected in series.

When the power supply is constant, the change of resistance in the parallel circuit will not affect the voltage of each branch.

The voltage at both ends of each branch in the parallel circuit is equal, yes, there is no contradiction, in the series circuit, the resistance increases, will the voltage increase?

If there are two or more resistors connected in series, and one of the resistors becomes larger, the voltage at both ends of the resistor will increase.

Is the voltage small if the current is small, and the voltage is high if the current is large?

If the resistance is unchanged, the current is small, the voltage is small, and the current is large, and the voltage is large. What about parallel circuits?

At any time, the relationship between the three is: i u r

If this parallel circuit is directly connected to the two poles of the power supply, the voltage will not change, which is the power supply voltage. If it is connected in parallel and connected in series with other resistors, the voltage at both ends of the parallel resistors will decrease because the total resistance of the parallel connection becomes smaller.

In a series circuit, the resistance is large, and the voltage is large, but in terms of the entire circuit, no matter how the resistance changes, the total voltage is always equal to the supply voltage. In this case, the current decreases due to the increase of resistance.

Is the voltage small if the current is small, and the voltage is high if the current is large? It is not said whether the resistance is constant or not, and of course it cannot be said that way.

In a series circuit, the current of each resistor is equal, and if the resistance is large, the voltage is also beaten. In parallel circuits, the voltages of all resistors are equal, and if the resistance is large, the current is small.

This depends on whether there are other electrical appliances on the main road, if there are other electrical appliances, then the voltage of each branch is to become larger. Otherwise, it doesn't change.

As the resistance increases in a series circuit, the voltage across the resistor increases.

It cannot be said that if the current is small, the voltage will be small, and if the current is large, the voltage will be large. This depends on whether the resistance in the circuit changes, if the resistance is constant, the current in the circuit is small, which means that the voltage of the circuit itself is small.

Regardless of whether it is a series circuit or a parallel circuit, all three satisfy i=u r

Well, in fact, this supplement that the teacher said is not very correct. A resistor r can also be said to be larger the resistor, the greater the voltage, but the voltage becomes a little larger. Here's how:

In addition to the external resistance r, the power supply also has its own internal resistance r, which is equivalent to being connected in series in the circuit. And let the power supply voltage be U, when there is an R in the circuit, the voltage at both ends of R = U*R (R+R), because R is very small and very small, the middle school textbook ignores it, so when there is only one external resistance R, the voltage at both ends of R = power supply voltage U, and its value does not change with the change of resistance R.

When there are more than 2 R in the circuit, the voltage at both ends of R = U*(R (R+R1)), so when R increases, the voltage at both ends of R will also increase.

Because in a series circuit, the currents are equal everywhere, according to Ohm's law i=u r, when the current through the conductor is constant, the voltage applied to both ends of the conductor is proportional to the resistance of the conductor.

So the greater the conductor resistance, the more voltage is distributed across the conductor.

Conversely, the smaller the conductor resistance, the less voltage is distributed across the conductor.

Because the currents are equal everywhere in a series circuit, according to U=I*R, the current i through all resistors is equal, so the larger the r, the greater the voltage at both ends, and there is a ...... r1:r2:r3=u1：u2：u3……