Calculate the voltmeter reading for this circuit with 2 sources and 2 resistors

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The discussion revolves around calculating the voltmeter reading in a circuit with two sources and two resistors. Initial calculations suggest a reading of 8 V based on a current of 2 A, but a participant argues the correct reading should be 12 V. The calculations involve determining the currents returning to each cell and the total current entering the voltmeter. Ultimately, the consensus leans towards 8 V being the correct reading despite the differing opinions. The thread emphasizes the importance of the original poster doing the majority of the problem-solving work.
songoku
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Homework Statement
Please see below
Relevant Equations
V = I.R
1685171477692.png


I find the current first, which is 2 A. Then the voltmeter reading would be 10 V - 1 x 2 = 8 V.

But the answer is 12 V.
I don't understand why it should be 10 + 1 x 2 = 12 V

Thanks
 
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I agree with your answer. It obviously cannot be more than 10V.
 
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Thank you very much haruspex
 
Yes, I agree, 8V is correct.
 
Current returning to cell A = x
Current returning to cell B = y
Current entering the voltmeter = z

10- 1*x=0
4- 2*y = 0
z = y + x

X=10
Y=2
Z=12

U=RI

1/R=1/1+1/2
1/R=1,5
R=2/3

U = (2/3)*12 = 8

The reading is 8 Volts.
 
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Welcome to PF, @erpelkon

erpelkon said:
Current returning to cell A = x
Current returning to cell B = y
Current entering the voltmeter = z

10- 1*x=0
4- 2*y = 0
z = y + x

X=10
Y=2
Z=12

U=RI

1/R=1/1+1/2
1/R=1,5
R=2/3

U = (2/3)*12 = 8

The reading is 8 Volts.
It is okay to offer alternate solutions to old schoolwork threads where the OP has already solved the problem. Please just keep in mind that in active threads, the OP must do the bulk of the work. We cannot offer solutions to them until after they have solved their schoolwork problem. Thanks. :smile:
 
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If have close pipe system with water inside pressurized at P1= 200 000Pa absolute, density 1000kg/m3, wider pipe diameter=2cm, contraction pipe diameter=1.49cm, that is contraction area ratio A1/A2=1.8 a) If water is stationary(pump OFF) and if I drill a hole anywhere at pipe, water will leak out, because pressure(200kPa) inside is higher than atmospheric pressure (101 325Pa). b)If I turn on pump and water start flowing with with v1=10m/s in A1 wider section, from Bernoulli equation I...

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