Electronic parallel voltage sources exercises?

In summary: I hope it's not too easy! :devil:Uh, where are the voltage sources?Uh, where are the voltage sources?
  • #36
I like Serena said:
Well, they are not all really "unknown" are they?
I think the leftmost one is 6 mA, don't you?
That doesn't sound "unknown" to me.

Oh, right *smacks forehead*


I like Serena said:
No, you will have to use KCL to find Io.


Alright, I see, give me a few moments to try and solve it...be right back with a scan
 
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  • #37
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  • #38
I like Serena said:
Well, they are not all really "unknown" are they?
I think the leftmost one is 6 mA, don't you?
That doesn't sound "unknown" to me.

Good point! lol... that was kinda silly of me.

Okay then... should be easy ...hope I'm not oversimplifying it (which I tend to do)...

http://img714.imageshack.us/img714/6847/600il.jpg
 
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  • #39
Femme_physics said:
Well I'd hate to start solving this 5 eq 5 unknown thing, but this is it right? I mean, this is what it boils down to?

PS Maybe a mod can move this topic to the homework section?

You can do it this way, but I think you would prefer the "smooth ride".

After calculating I_total, don't go back right away to your original circuit, but take the top diagram you drew in your scan, where you have 2 merged resistors.

There you can determine the voltage drop to the middle.

Only then, go back to the original circuit and calculate all the currents with Ohm's law.

Then, finally apply KCL to find Io.
 
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  • #40
I like Serena said:
You can do it this way, but I think you would prefer the "smooth ride".

After calculating I_total, don't go back right away to your original circuit, but take the top diagram you drew in your scan, where you have 2 merged resistors.

There you can determine the voltage drop to the middle.

Only then, go back to the original circuit and calculate all the currents with Ohm's law.

Much easier indeed! Well, I doubt we'd have somethign that difficult on the test thankfuly, and speak of the devil... I'm off to college in a jiffy :smile: wish me luck

XoX

Edit: Actually I don't want too early, I'll try and solve it
 
  • #41
Femme_physics said:
Good point! lol... that was kinda silly of me.

Okay then... should be easy ...hope I'm not oversimplifying it (which I tend to do)...

No, that won't work.

In your loop (a) you treat the current source of 3 mA as a voltage source of 3 V.
But that is not right.
The corresponding voltage drop is unknown.
 
  • #42
I like Serena said:
You can do it this way, but I think you would prefer the "smooth ride".

After calculating I_total, don't go back right away to your original circuit, but take the top diagram you drew in your scan, where you have 2 merged resistors.

There you can determine the voltage drop to the middle.

Only then, go back to the original circuit and calculate all the currents with Ohm's law.

Then, finally apply KCL to find Io.


http://img834.imageshack.us/img834/9089/wttt.jpg


Uhh...okay what am I doing wrong? o_O

btw got less than 30 minutes:rolleyes:
 
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  • #43
I wish you luck! :smile:
 
  • #44
Femme_physics said:
Uhh...okay what am I doing wrong? o_O

btw got less than 30 minutes:rolleyes:

Go back to the original circuit.

Now you have the voltage drop between a and b, so you can calculate the currents through the left and right resistor.

Same for b and the bottom.
 
  • #46
Femme_physics said:
Well this is my last attempt due to time shortage but I don't see how I find Io in any of this:

Good!
Do the same between a and b to find I1 and I2.


Aftward apply KCL at point B to find Io.
 
  • #47
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  • #49
:smile:

It seems that thread didn't have such a smooth ride!
 

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