How Does Nodal Analysis Determine Currents in a Circuit with Multiple Resistors?

[nisal5500]

Homework Statement

Using Nodal analysis, determine the current through each resistor, for this circuit. Could you please show the KCL working out.I need the answers Please help me i am helpless with nodal analysis consist of a current source.Thanks in advance :) !.please help me.

r1=120
r2=360
r3=330
r4=820
r5=100
r6=470
i1=15mA

Homework Equations

i1 + i2 + i3 = 0 ?

3) The attempt at a solution
first i converted the current sources and apply kcl for node 1.
For node1:
(9-v1)/120+(-4.95-v1)/560=0
so v1=7.41176v
For node 2:
v2/820+(5--v2)/570=0
so v2=3v.

I assumed that all currents are comming in.

I really want the answers please [/quote]

.
Please click on the image to zoom

 

[gneill]

Homework Statement

Using Nodal analysis, determine the current through each resistor, for this circuit. Could you please show the KCL working out.I need the answers Please help me i am helpless with nodal analysis consist of a current source.Thanks in advance :) !.please help me.

r1=120
r2=360
r3=330
r4=820
r5=100
r6=100
r7=470
i1=15mA

Homework Equations

i1 + i2 + i3 = 0 ?

3) The attempt at a solution
For the 1st question i gt v1=2.7794*10^-3v and v2=-0.072194v.

View attachment 55774


I really want the answers please

.
Please click on the image to zoom

You'll have to show an attempt so that we can know how to help; we won't do your homework for you here.

Presumably the list of resistances you've given are for the first circuit, but you've listed seven resistors when the circuit shows only six Also, it's difficult to make out the values on the voltage supplies from the image; you'll have to clarify them.

Start by identifying your reference node and labeling the others. Then make an attempt at writing node equations so we can see your level of understanding. If you have absolutely no idea what any of this means, you'll have to review your text and notes first.

 

[nisal5500]

You'll have to show an attempt so that we can know how to help; we won't do your homework for you here.

Presumably the list of resistances you've given are for the first circuit, but you've listed seven resistors when the circuit shows only six Also, it's difficult to make out the values on the voltage supplies from the image; you'll have to clarify them.

Start by identifying your reference node and labeling the others. Then make an attempt at writing node equations so we can see your level of understanding. If you have absolutely no idea what any of this means, you'll have to review your text and notes first.

first i converted the current sources and apply kcl for node 1.
For node1:
(9-v1)/120+(-4.95-v1)/560=0
so v1=7.41176v
For node 2:
v2/820+(5--v2)/570=0
so v2=3v.

 

[gneill]

first i converted the current sources and apply kcl for node 1.
For node1:
(9-v1)/120+(-4.95-v1)/560=0
so v1=7.41176v
For node 2:
v2/820+(5--v2)/570=0
so v2=3v.

It's not necessary to convert the current source; You're writing KCL equations for nodes, and the given current source just needs to be added to or subtracted from the current totals for the nodes it connects to. But it's okay to convert wish, it's just a bit of extra work for you. You should make clear what the converted source is. What's its potential, resistance, and orientation?

You haven't specified which nodes are which, so it's difficult to tell what your equations represent. Where's the reference node? Which node is node 1? Which is node 2? What's the value of the E1 source (looks like it might be 9V from the equations you wrote).