×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Voltage and power through steel pipe

Voltage and power through steel pipe

Voltage and power through steel pipe

(OP)
Dear people,

In my education I've had basic electronics. But there is 1 thing I never understood. If i have a voltage source, let's say 5 volt, and I connect a steel or coper wire directly from the plus to the minus, what will happen? Because if u calculate the resistance of the wire its extremely low and when u apply the law of Ohm, the current will be extremely high. Is this what happens?
This also happens when using a small steel pipe. I've simulated this with a small steel pipe of length 0.2m and radius of 0.003m which has a resistance of 1270 micro-ohms. Also, why is the voltage displayed as 2.44444V?


Kind regards,
Willem

RE: Voltage and power through steel pipe

The voltage is displayed in reference to the ground. Because the ground has connection with the circuit, it sort of becomes the mid point for the voltage.
The voltage will not equal 5V because of internal resistance of the battery.
Must be some kind of battery to be able to source close to 2MW of energy.

RE: Voltage and power through steel pipe

Usually there is a flash, sometimes a bang. Normally it also ruins the battery terminal and takes a chunk out of the conductor.

Look up battery internal resistance: https://data.energizer.com/pdfs/batteryir.pdf for example.

RE: Voltage and power through steel pipe

Did you have some reason for doubting Ohm's Law?

It looks like your simulation didn't actually have a ground reference, so the actual ground wound up roughly halfway between the negative and positive terminals of the battery; this is borne out by the fact that the negative end of the battery is shown as -2.5556 V, while the other terminal is shown as +2.4444, which, coincidentally add up to 5.0000 V, so no mysterious internal resistance is needed to explain the result. Note also, the current shown is nearly exactly 5 volt/1.270 milliohm = 3937.0079 amp, which, again, indicates that no internal resistance was modeled.

In any case, since you didn't model the internal resistance of the battery, you got an absurd current that a real battery can't produce. A real battery, ala AA, would have an internal resistance between 100 and 150 milliohm, resulting in between 10 and 15 A current into a dead short.



TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Voltage and power through steel pipe

Maybe congress is trying to repeal Ohms law, again.

RE: Voltage and power through steel pipe

by the way, "Voltage and power through steel pipe" is a terrible idea, in general, shorts, damage to circuitry, etc.; exposed live conductors (wires) is BAD, unless the circuit is specifically designed for something like that, like a digital volt meter

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Voltage and power through steel pipe

(OP)
Thank you all for the answers, as you said @IRstuff I completely forgot about the internal resistance so I got absurd results from my simulations (I've made other simulations aswell but this was just an example for the problem). Thank you for correcting me.

RE: Voltage and power through steel pipe

Dear Mr Willem19 (Civil/Environmental)(OP)21 Dec 22 10:23
"....I completely forgot about the internal resistance so I got absurd results from my simulations (I've made other simulations aswell but this was just an example for the problem)...."
I notice that so far all the learned advice are based on "electrical" such as Ohm's Law etc.... In view that you are from a different discipline/engineering (civil/environmental), we may not be looking/missed the core reason of your question.
It would be more fruitful if you are willing to disclose why are you carrying out this simulation? For what purpose/application ? With clear "objective" in mind, we may be able to assist.
Che Kuan Yau (Singapore)

RE: Voltage and power through steel pipe

Quote:

by the way, "Voltage and power through steel pipe" is a terrible idea, in general, shorts, damage to circuitry, etc.; exposed live conductors (wires) is BAD, unless the circuit is specifically designed for something like that, like a digital volt meter
Underground pipe thawing with a welder?

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close