## zachkt 3 years ago determine the potential difference Vxy in the circuit.

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1. zachkt

|dw:1348230038272:dw|

2. zachkt

srry hold on something went wrong

3. zachkt

let me add in the Voltage and resistor values

4. pitankar

sure

5. zachkt

|dw:1348230380036:dw|

6. pitankar

do you want me to give you the answer or the way to solve it?

7. zachkt

the way

8. pitankar

you know superposition?

9. zachkt

like a super node?

10. zachkt

Assuming you know the program "Multisim" i simulated this circuit and i have certain values already so I do not think i need to use a complex calculation. I guess my question is, what exactly in the circuit do i need to solve the potential difference Vxy

11. pitankar

ok! this problem can be solved using superposition theorem. which states, "In a linear network the overall response is the sum of the responses, one energy source acting at a time." So the approach to the problem is like this. first keep the source of 2V on and calculate the voltage at x and when you do this, short circuit all other voltage sources. Similarly repeat the procedure by keeping the 4V source on (on the extreme right) and short circuiting all other sources, find potential at y. now you have potential at X and Y and also the potential that bridges them, i.e 4V. see the polarity and add. you will get the answer

12. zachkt

so i just need to find the voltage at X and Y? then what?

13. pitankar

then you add the voltage as per polarity from x-3ohm-4V-3ohm-Y

14. zachkt

so i subtract the voltageX by 3ohms then subtract by 4V then subtract by 3ohms then subtract by voltageY?

15. zachkt

okay Voltage X is 1.2V and Y is 2.5, can you show me how to do the rest?

16. pitankar

Vx-4V-Vy 1.2-4-2.5 1.2-6.5 -5.3V Vxy = -5.3V

17. zachkt

now why is it Vx-4V instead of Vy-4V? is it because Vx is at higher potential ?

18. kashyapbharat48

Vxy = -.5

19. pitankar

no it's because when I go from X to Y I need to follow a convention. chose all voltage drops to be +ve and all voltage rises to be -Ve. So from X, the resistor gives me a voltage drop of 1.2V which I consider positive. The as I walk further I see a battery in reverse with 4V, since it is reverse, it gives me a voltage rise of 4V (-ve terminal is at lover potential to +ve, so it's a rise) and I consider it to be -Ve.

20. pitankar

and also dude, I have assumed that you chose the same convention to solve for voltages. The sketch you have uploaded doesn't show the right half properly, if possible redraw and i'll tell you the way to solve it

21. pitankar

@kashyapbharat48 seems to have solved it.

22. zachkt

that was all that was drawn in the problem, so that is all the information i know. I then had to use a computer program to simulate the circuit and i have the values of the voltages at X an Y

23. zachkt

how is it -0.5?

24. kashyapbharat48

whats the correct ans?

25. zachkt

i do not have the correct answer, I just want to know how you solved that?

26. kashyapbharat48

try the superposition method u'll get it

27. MillerZ

the correct solution is:

28. MillerZ

Vy-Vx=-3.7V

29. MillerZ

30. MillerZ

review the file...