10-21-2001, 02:40 PM | #1 |
Thoth - Egyptian God of Wisdom
Join Date: August 16, 2001
Location: UK
Posts: 2,891
|
I am writing a Physics test on Thursday, and am kind of stuck on this point.
We are doing (among others) high voltage cables and why we use them. Now, I have a question. The resistance of the cables would be Resistance = rho * length/area (R=rho * l/A), rho being the resistance factor of the material. Now, you also calculate the resistance by Resistance = Voltage/Amperage (R = U/I). However, of course, if you change the voltage the resistance of the cables would change, but that is impossible because they are a fixed length, area and material! HELP!!! What changes? What IS the resistance I got in the second computation? ------------------ Sapphire Dragoness of ALSB Waitress at Cloudy's Cafe Guardian of the Temple of Aerie (specialized in GenCon and BG) Magess of Lady Lioness' Court Saint of the SoS Historian of IW Most Illustrious Arch-Magess of the Illuminati Lux omnis est Once Upon A Paper Writer's Forum |
10-21-2001, 02:47 PM | #2 | |
Zartan
Join Date: March 11, 2001
Location: North Carolina USA
Age: 57
Posts: 5,177
|
Quote:
That would be the resistance of my thick skull, and your trying to run this question through it ------------------ "The Martyr" (excerpt) There is sobbing of the strong, And a pall upon the land; But the People in their weeping Bare the iron hand: Beware the People weeping When they bare the iron hand. --Herman Melville (written after the assasination of President Abraham Lincoln) |
|
10-21-2001, 02:48 PM | #3 |
Unicorn
Join Date: October 4, 2001
Location: Kingdom of the West,..P.o. Cynagus
Posts: 4,212
|
It's been a few thousand years since I had to deal with this, but if you change voltage the current changes.
|
10-21-2001, 02:52 PM | #4 |
Guest
Posts: n/a
|
I wish you good luck since I can't help you.
I'm in the second class of high school you know! ------------------ Where there are monsters and barbarians there will be Byronas fighting against them. |
10-21-2001, 03:00 PM | #5 |
Thoth - Egyptian God of Wisdom
Join Date: August 16, 2001
Location: UK
Posts: 2,891
|
I'm in 10th - when does High School start in Greece? I hope I didn't mess the whole thing up - I had to translate all the technical terms from German into English, I may have gotten some wrong.
|
10-21-2001, 03:02 PM | #6 |
Guest
Posts: n/a
|
A man starts high school in Greece after 6 years in primary school.
------------------ Where there are monsters and barbarians there will be Byronas fighting against them. |
10-21-2001, 03:03 PM | #7 |
Account deleted by Request
Join Date: May 17, 2001
Location: .
Age: 38
Posts: 8,802
|
Ack! Not physics! I'm allergic to that! Save meeeeee! I'm meeeeeeeeeltiiiiing!
|
10-21-2001, 03:15 PM | #8 | |
Thoth - Egyptian God of Wisdom
Join Date: August 16, 2001
Location: UK
Posts: 2,891
|
Quote:
------------------ Sapphire Dragoness of ALSB Waitress at Cloudy's Cafe Guardian of the Temple of Aerie (specialized in GenCon and BG) Magess of Lady Lioness' Court Saint of the SoS Historian of IW Most Illustrious Arch-Magess of the Illuminati Lux omnis est Once Upon A Paper Writer's Forum |
|
10-21-2001, 03:26 PM | #9 | |
Red Wizard of Thay
Join Date: August 21, 2001
Location: Limburg, Netherlands, Europe
Age: 42
Posts: 894
|
Quote:
Hope this helps, if you have more physics questions, just shoot, I'm in this business ------------------ Lady Menqel, Protector of IW's, smiter of evil http://www.angelfire.com/rpg2/mirac - Priest of Helm - Fellow Table Dancer of the Jerome's Table dancer group - Spell formulater of the IW peace-keeping force - Magical advisor of MiLady Lioness - Thanks to Sazerac for the great sig picture |
|
10-21-2001, 03:39 PM | #10 |
Thoth - Egyptian God of Wisdom
Join Date: August 16, 2001
Location: UK
Posts: 2,891
|
Hm... but if I have both U and I and they do not add up to the R I got by rho*length/Area? To be more exact, something like this
R = rho * l/A R = U/I rho = 0.017 l= 100km A = 0.8 cm2 U = 150kV I = 533.33 A Therefore R = rho * l/A R = 0.017 Ohm per whatever * 100km/0.8cm R = 212500 Ohm HOWEVER R = U/I R = 150000V/533.33A R = 281.25 Ohm WHAT THE HECK? THE RESISTANCE CAN'T BE 212500 Ohm AND 281.25 Ohm AT THE SAME TIME!!!! *sob* ------------------ Sapphire Dragoness of ALSB Waitress at Cloudy's Cafe Guardian of the Temple of Aerie (specialized in GenCon and BG) Magess of Lady Lioness' Court Saint of the SoS Historian of IW Most Illustrious Arch-Magess of the Illuminati Lux omnis est Once Upon A Paper Writer's Forum |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Britney's Guide to Semiconductor Physics | GokuZool | General Conversation Archives (11/2000 - 01/2005) | 9 | 04-28-2004 11:17 AM |
Cartoon Laws of Physics | InjaYew | General Conversation Archives (11/2000 - 01/2005) | 7 | 01-20-2004 05:26 PM |
An Article of stupid movie physics ... | Arvon | General Conversation Archives (11/2000 - 01/2005) | 8 | 10-24-2003 08:46 AM |
Quantum Physics? | DJG | General Conversation Archives (11/2000 - 01/2005) | 10 | 05-06-2003 03:29 PM |
The Laws of Cat Physics | Garnet FalconDance | General Conversation Archives (11/2000 - 01/2005) | 6 | 02-13-2002 05:02 PM |