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These are some ideas for block 6. In exercise 1 remember the two formulas that you have to use.

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When you have a series-parallel combination like in question C, first you have to solve the branches

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that are in parallel. For this you have two resistors that are in series of 50 ohms and

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then solve the two branches that are in parallel. Here you have the results. This is the first

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operation you have to do and you get this result but this is not the equivalent resistance is the

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inverse that is the investor you have to look for this button in your calculator that says to you

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which is the inverse of a fee of a number finally you add these two figures 10 and 15 in question

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one F the first thing you have to do is to add these two figures 10 and 30 you

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get this preliminary result 40 ohms then you have two branches in parallel there

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are 40 ohms each use the formula of parallel and parallel resistors and then

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you have the equivalent resistance here that is 20 ohms and finally add these three figures and

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you will get the result exercise two is more complicated first in my opinion you have to

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number all the resistors resistor one two three four and five the first thing you have to do is

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to calculate equivalent resistance to do so you have to add these two resistors that are in series

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20 and 10 and then you have two branches one there are three and four and five so make this

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calculation 1 divided by 60 plus 1 divided by 30 you get this result and the inverse is 20 ohms

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then you can add the three figures 100, 150, and this 20 ohms.

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So your equivalent resistance is 270.

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Next step is to calculate the intensity through all the CKIT.

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Remember that this is the intensity that is flowing in this branch and also in this branch.

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the total intensity is the voltage of the cell divided by the equivalent resistance so you get

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the result and then they are asking you all the intensities that are flowing through each resistor

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in resistor one you have the intensity of the c kit in resistor two you also have it but here

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it's divided in two branches to calculate it through the arms law you need to know the voltage

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that is left in this resistor we know that we have 10 volts that is being used through resistor 1

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resistor two and here between in resistor three you have the same voltage between these two points

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and between this and this so what i'm going to do is to calculate voltage in resistor one

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in resistor two and then the left is um the amount that is left between these two points

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is going to be resist the voltage in resistor three here you have the calculations so voltage

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in resistor one is the total intensity by resistor one so you have 3.7 volt in resistor voltage in

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resistor 2 is 5.6 volt you add these two figures and you get that you are using already 9.25 volts

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so the remaining that i have is 0.75 volt so the voltage in resistor three is 0.75 volts

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with the ohm's law you can calculate the intensity that is going through this resistor

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voltage divided by resistance 0.75 volts divided by 60. you have this uh intensity the intensity

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in the other two resistors is equal because they are in series in the branch that is in

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parallel with resistor 3 and you can calculate making this difference the intensity that you

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have in in the origin in your in your cell and you make this subtraction with

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the intensity number three and then you can get these results check that you

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have these results finally in all your resistors in exercise three we have two

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resistors that are in series with three in parallel. The first thing to do is to

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calculate equivalent resistance. Here we have to

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calculate these three branches that are in parallel and this is the operation

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you have to do. The three resistors are equal so the result is 3 divided by 30

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but the equivalent resistance is the inverse that is 30 divided by 3 that is 10 ohms so you add this

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figure to the other two 200 and 100 and the equivalent resistance is 310 ohms um as these

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two resistors are in series the intensity that is going to be the same and equal to the total

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intensity we calculate as always with the voltage of the cell divided by equivalent resistance and

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is 0.08 ampers. With this figure we can calculate the voltage that is

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being used by these two resistors 1 and 2. You have to calculate exactly the same as you have

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on in the previous exercise with the ohm's law voltage in one is the intensity by resistance

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is this figure and voltage in two is this figure so you can calculate the addition of these two

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voltages and the remain with the voltage of the cell that was 25 volts is the voltage that you

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have involved in the resistor number three um now you have the voltage that you have in this

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in these three uh here in these three resistors because it's the same the voltage in resistors

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three four and five as they are equal and they are in parallel is the same and finally you have

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to calculate the intensity that is going through these three resistors but it's this is very easy

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because the total intensity that is coming through this way is divided into these three branches as

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the three resistors are equal the intensity through them is going to be the same and it's

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going to be the third of the total intensity so finally you have here the results that we're

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asking in the exercise number four you have two branches in parallel and one resistor number one

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that is of one kilo ohm be careful uh i think this was a mistake from the book because it's

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uh very big well uh first of all as always a total equivalent resistance

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are these two figures in each brand so you have three plus two five and four plus five nine volts

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so uh these two in parallel uh one divided by you have this result that is 0.31

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and the inverse of this is 3.21 that you have to add to the resistor number resistance number one

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that is one thousand ohms so this is your strength sphere of the equivalent resistance the total

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intensity it's always voltage divided by resistance you have this figure almost nine milli amperes you

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can um seek out it well the third question is the voltage across is each resistor to calculate it

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we need to know uh which is the voltage that's be it's being used by resistor one and you can

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calculate because you know that the intensity that is flowing through this resistor is the

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total intensity so you multiply it whatever for by the value of the resistance and you have 8.97

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volts that is almost the whole uh nine volts that you have in the in the cell so

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So the remaining voltage, that is this amount, that is 29 millivolts, is used by these two branches.

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But the voltage in each of them is not the same because the four resistors are different.

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What we have to calculate now is the intensity that is going through each of the branches with this value of 29 millivolts.

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Then we can calculate with the Ohm's law. Well, I have done it with intensities divisor, but you can also calculate it with the Ohm's law.

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You have these two intensities making this average here and finally you can calculate the voltage in each of the resistors. As you can see the voltage in these four resistors is really small and the intensities are equal to light 2.