Can't figure it out

WBahn

Joined Mar 31, 2012
33,186
I'll be happy to validate you once you have addressed the units issue (as anyone around here can confirm, I am big on tracking units properly) and a few other things.

You need to:

1) Turn your expressions into equations by giving them an appropriate left-hand side (LHS).

2) Correct the "μΩ" units in those places where they should be "μS".

3) Add units in the places where you have omitted them (such as the RHS of line 4, which has units of MΩ, and the RHS of line 7, and all four lines where you calculate the individual currents).

4) Add a "Checks" section to the end of your work in which you check your answer by adding up all four currents and comparing the total to the given total current. Get in the habit of putting checks like that at the end of every problem you can, even on exams (especially on exams!). You will catch almost all your errors and even if you can't correct the work (out of time on an exam, for instance) you will often get significant partial credit for catching the error.
 

Thread Starter

emagdnim47

Joined Jul 16, 2011
21
I'll be happy to validate you once you have addressed the units issue (as anyone around here can confirm, I am big on tracking units properly) and a few other things.

You need to:

1) Turn your expressions into equations by giving them an appropriate left-hand side (LHS).

2) Correct the "μΩ" units in those places where they should be "μS".

3) Add units in the places where you have omitted them (such as the RHS of line 4, which has units of MΩ, and the RHS of line 7, and all four lines where you calculate the individual currents).

4) Add a "Checks" section to the end of your work in which you check your answer by adding up all four currents and comparing the total to the given total current. Get in the habit of putting checks like that at the end of every problem you can, even on exams (especially on exams!). You will catch almost all your errors and even if you can't correct the work (out of time on an exam, for instance) you will often get significant partial credit for catching the error.
I can't thank you enough! You guiding me through every detail is just superb. I've attached my revised work. I wasn't sure about the RHS line being in MΩ? I put it there anyways just in case, correct me if I'm wrong would be incorrect to leave RHS line 4 w/ just the Ω instead?
 

WBahn

Joined Mar 31, 2012
33,186
I can't thank you enough! You guiding me through every detail is just superb. I've attached my revised work. I wasn't sure about the RHS line being in MΩ? I put it there anyways just in case, correct me if I'm wrong would be incorrect to leave RHS line 4 w/ just the Ω instead?
Looks like you forgot to attach your revised work.

Line 4, where your RHS is just 0.05319, needs to have units since it is a resistance. It is NOT 0.05319Ω and it is NOT 0.05319kΩ (which would be 53.2Ω), it is 0.05319MΩ (which would be 53.2kΩ).

And, yes, it is incorrect to leave out the multiplier M. Trust me, you would rather get tangled up with 0.05V than 0.05MV !
 

Thread Starter

emagdnim47

Joined Jul 16, 2011
21
Looks like you forgot to attach your revised work.

Line 4, where your RHS is just 0.05319, needs to have units since it is a resistance. It is NOT 0.05319Ω and it is NOT 0.05319kΩ (which would be 53.2Ω), it is 0.05319MΩ (which would be 53.2kΩ).

And, yes, it is incorrect to leave out the multiplier M. Trust me, you would rather get tangled up with 0.05V than 0.05MV !

Thank you for clarifying, I'm going through the class online and I haven't seen material that covered those particular prefixes until I looked up their meaning via the web. It seems you right of course, strange though you'd figure they'd cover these in the course.

Apologies about not attaching the revised work. Heres problem # 2 attached, thank you again!!! PLease let me know if there's anything else I may have missed.

Alex
 

Attachments

WBahn

Joined Mar 31, 2012
33,186
You are very close. You are still starting off with three expressions, not equations. Set each one of those equal to Req on the LHS.

You have a units error (probably just a typo) on the line just above E=319V.

In the second line of your Checks you leave off the units entirely. Don't do that!
 
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