Inspection and Testing Exercise

[rustynails]

Allright ppl,

I've bought this book and have stumbled working on exercise 2 p174 (if anyone has the book). In particular the completion of the test results for the given circuit, which is a 63m ground floor socket circuit consisting of 8 socklet outlets wired in 2.5/1.5 pvc twin and earth. 2.5 resistance is 7.41m and 1.5 resistance is 12.10m, giving total resistance of 19.51 per metre.

So
r1 = 63 * 7.41 / 1000 = 0.46
r2 = 63 * 12.10 /1000 = 0.76
rn = 63 * 7.41 / 1000 = 0.46

So I calculate R1 + R2 = 0.46 + 0.76 / 4 = 0.31

But the book says its 0.08?

 

[telectrix]

can't fault your answer.

 

[trev]

Well whatever mistake you may be making, although I can't see any problem with it, I'm making the same one because no matter which was round I do it I get the same as you.
What does the worked answer say please mate

 

[JUD]

Agree with Tel and Trev. Your answer is correct.

Mistake in the book I say.

What does the worked answer say please mate

I have the book and I think the OP is referring to a Schedule of Test results specimen in the answers section at the back.

It's been filled in with values r1 = 0.46, rn = 0.46 and r2 = 0.76 but an R1+R2 value of 0.08

 

[Dipzy]

Mistake in the book, wouldn't be the first time.....

 

[tony mc]

Its not the Chris Kitcher book is it ?

As you will find quite a few errors which IMO keeps you on your toes as it shows you are getting a true understanding of what you are doing!

 

[trev]

It's a bit crap when a book which is supposed to help you through a course and exam contains glaring errors though isn't it?

 

[rustynails]

It's a bit crap when a book which is supposed to help you through a course and exam contains glaring errors though isn't it?

Yep

Glad I got that cleared up tho. :biggrin:

 

[trev]

I think I'd email the author and ask him to justify his answer, but then again like the kids say I'm a grumpy old git

 

[tony mc]

Just had a look and it is the book!

I think you will find quite a few more errors see if you can find the PFC from the info given on exercise 6 page 178 !!

 

[Guitarist]

I find it extremely annoying when working through "examples" in these books, only to find that there is no way I can get the same answers. Eventually, one has to conclude that the book is in error (or end up with underpants on ones head and pencils up ones nose).
Do these authors never proof-read their own books?

 

[tony mc]

I wonder how many members will dust off the said book and have a look!

Mind you its most likely me that wrong and the PFC value is looking at me (Wood trees etc comes to mind) !!!

 

[trev]

Post the question up then mate. Lets all have a look

 

[Guest123]

I've heard nowt but bad things re this Chris Kitcher book.

Apprently it is full of errors throughout.

 

[telectrix]

it does have errors, but it's still a very good book. even the bible has errors. LOL. :bucktooth:

 

[Paul.M]

Haven't they sorted out that book yet? It had these same problems in the 16th ed of it.

 

[tony mc]

Post the question up then mate. Lets all have a look

Its a schedule of test results with blanks in.

Tried to upload a photo of the table but I can't seem to get the thing to work!

 

[Guitarist]

Haven't they sorted out that book yet? It had these same problems in the 16th ed of it.

Do you think Chris is bothered about the errors if it is selling copies?
I was really excited about my copy a few months ago, but quickly became disappointed with the number of errors in it. I've lost faith in whether it is correct or not now. Shame really.

 

[mickys86]

Errors in the answers or not, seems like a book full of exercises sounds like fun. Bit Like the sudoku in the paper. I might look into this book.....

 

[telectrix]

only ever tried that sudoku once. should be renamed sodit, cause that's what i said after 3 minutes. cannot do them, same with that rubik cube, had one when they first came out. it went over next door's fence.