Hello,

I'm trying to verify that I correctly calculated the power in R5 shown in the circuit below.



I first determined that the voltage over R5 is 4.91 v. Then I calculated power as P = (V^2)/R5 = 4.3 mW. I would greatly appreciate it if anyone could verify my calculations. Thanks!

 

Show us your calculations........

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Eccentric millionaire financed by 'er indoors

 

 

R5 isnt in parallel with R3/R4......See your third line

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Eccentric millionaire financed by 'er indoors

 

Thanks for your help. It looks like I should have had R5 in parallel with R2.

So then VR5= (R2||R5 + R3||R4) / (R1 + R2||R5 + R3||R4).

Does that seem reasonable?

 

Calc the value of R3 in parallel with R4 (514.29 ohms)....add R2 to that ( 144.29) , then calc that result in parallel with R5...(950.14)...call that Rz
Add that to R1...

Calc the current Iw thru R1+Rz...

then Pdiss in R5 = Iw squared*R5

__________________
Eccentric millionaire financed by 'er indoors

 

Why don't you use mesh analysis? you do the three meshes find the current thru R5, and you're done, it will be very fast if you use a graphing calculator.

 

I'm afraid that I haven't studied mesh analysis at all. But I'll look into that; thanks.

 

Actually, what I'm really trying to verify is the following:

for the circuit I originally posted.

Thank you.

 

deleted my answer

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Eccentric millionaire financed by 'er indoors

 

As I see it, it's good, you'll get a the result, as long as you don't make a mistake with the numbers.

 

Thanks. I'm studying for an exam and this is one of the things that was causing some confusion for me.

 

As you see, there's a bunch of people here that can help you, hope you do it good.