simple application of nodal analysis

Hi,

Almost all the details you will find in the given link below:
https://img710.imageshack.us/img710/1565/exampleproblemnodalysis.jpg

You will find the expected (or, target answers) in the top right corner.

As you can see my value for V1 is utterly wrong. It should have been 37.818V according to the answer given in the book. I have checked my equations several times but I found nothing wrong with them. Please help me with it. Many thanks for your help.

Cheers

The way you have tried to solve the final system of equations looks strange.

Try this way:

3A - 2B = 48
10A - 14B = -80

Multiply the first equation by 7:

21A - 14B = 336
10A - 14B = -80

And subtracting the equations gives:

11A = 416

=> A = 37.818

After this it is easy to solve for B

3*37.818 - 2B = 48

=> 2B = 113.454 - 48
=> B = 32.727

Thanks a lot, misterT. It was very nice of you.

That means there was nothing wrong with the equations but the method I chose to solve them messed up the answer. I used Cramer's rule. But surprisingly there is nothing wrong with the Cramer's rule's application; I have checked it. Don't know what's going on. If you are familiar with the Cramer rule, then please have a look and let me know where I went wrong.

Many thanks.

PG1995 said:

If you are familiar with the Cramer rule, then please have a look and let me know where I went wrong.

Click to expand...

Oh yes, you have written -4 where it should be -14. Same mistake in three different places. Look carefully.

Many, many thanks, misterT. I'm going to fail tomorrow's exam. I keep on making these trivial mistakes which alters the entire answer.

Best regards
PG