volatages across series-parrallel ciruit.

[M.Samad-CNAQ-]

https://i52.tinypic.com/11loqy0.png

Need to Find Voltages across Va,Vb,Vab and current flowing from V1.

idk how to find voltages across points in series-parrallel comb but i think i can find voltages across resistors by formula Vx=Rx/Rt x E.but do it guna help?and current tflowing from v1 will be 12v/Rt?

just a expecting a little bit of formula and idea.

 

[Ratchit]

M.Samad-CNAQ-

It appears you need some more basic study because you seem so unsure of yourself. Come back when you have more confidence, and also bring an attempted solution. By the way what is the reference point for Va and Vb?

Ratch

 

[tazman171]

First off that is a series aiding circuit which is handled by Kirchoff's Voltage Law or Kirchhoff's Current Law (KVL or KCL).

Using Ohm's law of series and parallel circuits we know the total ohms will be smaller than the sum of the smallest branch resistance (ohms), in the case of these 2 parallel branches, the current is inversely proportional to the resistance of each branch.
Your total Ohms is easy, add Ri to R2, 32k Ohms R3 and R4, 32k. You have 32k Ohms on each branch, you could use the reciprocal method to get the totals but seeing as its only 2 branches you can go 32k x 32k/32k + 32k = 16k Ohms total resistance, but that method only works for 2 parallel branches.

So 16k ohms total but with 28V as it's a series aiding circuit, thus the voltages add to each other. 28V/16k ohms = 1.75mA for total circuit amperage. Voltage drop on each branch will be 1.75 mA/2= .875 mA x R1 gets you it's Vd, sub that from R2 for the Vd across it. Repeat for the other branch.

At points A and B your readings will be in regards to a reference point, with out knowing that it could be 4V or .6 V or some where in between. You're getting into Thevenin's, Norton's, Millman's and other network theorems. "Thevenising" circuits tends to make me curl up in a corner and cry so I'll stop here.

Later

 

[Jugurtha]

Hello,

Adding some Fine Artwork to what Tazman said (He actually solved the Home work so you shouldn't have any other problems...But just in case, here's a schematic attached to make it clearer)

https://i52.tinypic.com/11loqy0.png

Need to Find Voltages across Va,Vb,Vab and current flowing from V1.

idk how to find voltages across points in series-parrallel comb but i think i can find voltages across resistors by formula Vx=Rx/Rt x E.but do it guna help?and current tflowing from v1 will be 12v/Rt?

just a expecting a little bit of formula and idea.

 

[tazman171]

Hello,

Adding some Fine Artwork to what Tazman said (He actually solved the Home work so you shouldn't have any other problems...But just in case, here's a schematic attached to make it clearer)

Nice Jugurtha! Always easier to explain with a schematic.