Actually OD of 0.70 is closer to matching the circumference. Plus, I anticipated that by rounding downwards, would tend to make the round tube have slightly higher inductance.
For density calculations, the ratio of ribbon cross section area to tube cross section area is approx 0.55 Yes, you correctly noted, I should have made the tube's wall thickness 60 mils, NOT 120 mils. But, I was not addressing effect/weight, but rather the comparison effect/shape. Robert > In message <[email protected]>, dated > Thu, 5 Nov 2009, [email protected] writes: > >>solid ribbon copper conductor, 1 inch wide and 120 mils thick >> copper tube, 0.75 inch outside diameter and 120 mils wall thickness >> >>The two circumferences are approximately the same. >> Rectangle 2 * (0.12+1) = 2.24 inches >> Tube pi * 0.7 = 2.20 inches > > Why 0.7? The OD is 0.75, giving a circumference of 2.36 inches. > > Also, the criterion used to claim that flat is better is 'circumference > per kilo(gram)'. What are the lineal densities of your example > conductors? > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK > Help stamp out intolerance! > > - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
