Resistor Circle

[mpaap]

well now that's a part where im not so good in..
If Vdrop is 5ohms * 4A then it's 20V
so R12 = 20V ?
R1 = R2 = 10V ?

 

[ericgibbs]

well now that's a part where im not so good in..
If Vdrop is 5ohms * 4A then it's 20V
so R12 = 20V ?
R1 = R2 = 10V ?

No, dont forget you have calculated the parallel value for R1 and R2

so its just 5 ohms,, as U1 =44V the the drop across R1 and R2 is 20V.

You now know the voltage across R6, which is 44-20 = 24V

so calculate the current thru R6.....?

 

[mpaap]

now it's getting confuseing.
okei, R6 is 10 ohms and voltage is 24 ohms..
then i think I = 10 / 24 = 2,4A ?
am i right?

 

[ericgibbs]

now it's getting confuseing.
okei, R6 is 10 ohms and voltage is 24 ohms..
then i think I = 10 / 24 = 2,4A ?
am i right?

Good, thats correct.. 2.4A
So the next step is to work out the current thru R3 R4 and R5

You have already worked out that all together R3,4 and 5 are 15Ohms

so whats the current thru this 15 ohms, you know the voltage is 24V

I = 24V/15R =...... ?

 

[mpaap]

okei, 24V / 15R = 1,6 ohms
so R345 = 1,6 ohms ?

o yes, my bad.. 1,6A ?

 

[ericgibbs]

okei, 24V / 15R = 1,6 ohms
so R345 = 1,6 ohms ?

Its actually 1.6 Amps not ohms.

You are almost there!

You know now the current is 1.6Amp

so work out the voltage drop across the R3 resistor

Vdrop= 1.6A * 10R = ........ ?

 

[mpaap]

Voltage drop across the R3 = 1.6A * 10R = 16V ?
that means R3 is 16V ?

So R4 = R5 = 4 V?

 

[ericgibbs]

Voltage drop across the R3 = 1.6A * 10R = 16V ?
that means R3 is 16V ?

ok, just one more step and youre done.

Across R4 and R5 is 24V - 16V = 8V

so now work out the current thru R4..

I= 8V/10R =..... ?

The R5 is the same.!

Now fill in the question list and post it.

 

[mpaap]

R4, i = 0.8 a?

 

[ericgibbs]

R4, i = 0.8 a?

Correct.

So now put the values you have calculated into that circuit diagram you first posted, lets see it.

 

[mpaap]

I = 4A, U = 44V and R = 11 ohms
I1= 2A U1= 10V
I2= 2A U2= 10V
I3= 1,6A U3= 16V
I4= 0,8A U4= 8V
I5= 0,8A U5= 8V
I6= 2,4A U6= 24V

Am i right?

 

[ericgibbs]

I = 4A, U = 44V and R = 11 ohms
I1= 2A U1= 10V
I2= 2A U2= 10V
I3= 1,6A U3= 16V
I4= 0,8A U4= 8V
I5= 0,8A U5= 8V
I6= 2,4A U6= 24V

Am i right?

All ok except U1 and U2, remember the first voltage drop you calculated..

 

[mpaap]

o yes.. U1 = U2 = 20V..
im going to do it one more time by myself.
Thanks a lot for your help
I was looking for help from everywhere.

 

[ericgibbs]

o yes.. U1 = U2 = 20V..
im going to do it one more time by myself.
Thanks a lot for your help
I was looking for help from everywhere.

Well done.

Thats it, now rework all the calculations from the beginning so that you fully understand.

You can use the same method to solve most resistor circuits.

Good Luck.

 

[mpaap]

Thanks ericgibbs
i did it this time alone, and yout method rocks !!
i don't know how to thank you man
Respect+ !

Edit: Does someone have any that kind exercises that i could do? I would really like it... going to have big test soon.

 

[EN0]

You want practice, eh? Here you go!

Ohm's Law Practice Problems #1 - Learning Activity

Ohm's Law Practice Problems #2 - Learning Activity

Ohm's Law Practice Problems #3 - Learning Activity

Ohm's Law Practice Problems #4 - Learning Activity

Ohm's Law Practice Problems #5 - Learning Activity

Here is the main source:

**broken link removed**

If that's not enough, let me know.

 

[mpaap]

Thanks ElectroNerd!
Im open for more