How Should a Copper Wire Be Cut to Achieve Specific Resistances?

  • Thread starter Thread starter Surfersara12
  • Start date Start date
  • Tags Tags
    Length Resistors
Surfersara12
Messages
1
Reaction score
0
Questions: A certain copper wire has a resistance of 10.0 Ω. At what fraction of the length L must the wire be cut so that the resistance of one piece is 5.0 times the resistance of the other?

What is the resistance of the longer piece? Shorter piece?

I am completely lost on this. i know it should be fairly simple and I think I have to use the equation R= p*l/A
 
Physics news on Phys.org
Resistance is proportional to length, so you just need one piece to be 5 times the length of the other.
 
Thread 'Need help understanding this figure on energy levels'

Thread 'Need help understanding this figure on energy levels'

This figure is from "Introduction to Quantum Mechanics" by Griffiths (3rd edition). It is available to download. It is from page 142. I am hoping the usual people on this site will give me a hand understanding what is going on in the figure. After the equation (4.50) it says "It is customary to introduce the principal quantum number, ##n##, which simply orders the allowed energies, starting with 1 for the ground state. (see the figure)" I still don't understand the figure :( Here is...
View full post »
Thread 'Understanding how to "tack on" the time wiggle factor'

Thread 'Understanding how to "tack on" the time wiggle factor'

The last problem I posted on QM made it into advanced homework help, that is why I am putting it here. I am sorry for any hassle imposed on the moderators by myself. Part (a) is quite easy. We get $$\sigma_1 = 2\lambda, \mathbf{v}_1 = \begin{pmatrix} 0 \\ 0 \\ 1 \end{pmatrix} \sigma_2 = \lambda, \mathbf{v}_2 = \begin{pmatrix} 1/\sqrt{2} \\ 1/\sqrt{2} \\ 0 \end{pmatrix} \sigma_3 = -\lambda, \mathbf{v}_3 = \begin{pmatrix} 1/\sqrt{2} \\ -1/\sqrt{2} \\ 0 \end{pmatrix} $$ There are two ways...
View full post »

Similar threads

Calculating Copper Wire Gauge for Resistance Thermometer Bridge Circuit
Replies
6
Views
2K
Electrical Circuits - Parallel vs. Series
Replies
14
Views
1K
Long distance electrical transmission efficiency
Replies
2
Views
2K
Resistance is known. Length of wire?
Replies
2
Views
2K
Why Does Recalculating Resistance of Resistors Yield Different Results?
Replies
3
Views
2K
Platinum resistance thermometer and Kirchoff's Laws
Replies
1
Views
3K
How to Calculate the Diameter of a Copper Wire Given Its Resistance and Mass?
Replies
4
Views
4K
What is the resistance of copper wire?
Replies
14
Views
15K
  • Poll Poll
Finding Length and Area of Tungsten Wire Resistor
Replies
1
Views
6K
How to find the radius of copper wire given resistivity values
Replies
1
Views
23K

Hot Threads

Recent Insights

Back
Top