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How to calculate the total resistance for this figure?

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danesh

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total resistor

hi,
can i know hw to calculate the total resistiance for the given figure. Please guide through the calculation process.
 

Re: total resistor

It is easy. Just write currents form + to - and you will see where is parallel an where serial connection.
 

Re: total resistor

This network has three independent loops and three independent nodes. You will have to do the classical three simultaneous equations and solve for the current from the battery. Then R=E/I
 

Re: total resistor

or you can do superposition principle. first you assumed that you have 2 supply sources of 10 V each. so the circuit will look like the following.


...............10V
.................|
.................1k
.............../....\
............../.......2k
............./......../...\
...........3k......2k....2k


and another circuit

.....................10V
......................|
.....................2k
.................../....\
................2k......\
................/..\.......\
..............1k...3k.....1k


just find the node voltage of the 2 circuits and add them together. once you know the voltages of all the nodes, then you can find the current across each resistor and also your final input total resistance.
 

Re: total resistor

simply u could convert the resistances in Π connection
to star connection
the problem would be so easy
 

Re: total resistor

This makes things difficult. I am certain I have never seen an oddball resistor network such as this in any schematics. Anyways, a good approximation for your circuit is to calculate the voltages without the cross resistor. Then you will get 7.5 on one side and 5 on the other.
 

Re: total resistor

It's a classic. Google for 'Wheatstone Bridge' to understand the circuit.
Regards, ep20k.
 

Re: total resistor

man it is unbalanced wheatstone bridge

let X and Y donate the points of the bridge arms i.e


X-----------^^^^^^^--------------Y
then Vx=((3k)/(1k+3k))*10 >>>voltage division rule Vx w.r.t ground

Vy=((2k)/(2k+2k))*10 >>>voltage division rule Vy w.r.t ground

so Ix=Vx/Rx=(15/2)/(3k)=5/2 mA & Iy=Vy/Ry=(5)/(2k)=5/2 mA

So total current I=Ix+Iy=5mA

Vtotal=I*Rtotal=10=5mA*Rtotal so Rtotal =2k answer

ithis solves the problem
 

Re: total resistor

U can use the NODE Substion method to calculate the total I then R=V/I
 

Re: total resistor

r1,r2 and r5 form a delta n/w convert it into a star n/w then the resistors r2\3 and r4 will become parallel to each other.
 

total resistor

R1 ,R2, R5 r delta connected.convert into star.
 

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