How Does Wire Diameter Affect Electrical Resistivity?

[cemx]

I need your help to finish my homework.I have only two questions

1-If a diameter of a wire is doubled,what happens to its electicial resistivity?

2-Why is different the resistivity of materials?

Thanks

 

[xxChrisxx]

What do you think?

 

[NBAJam100]

I need your help to finish my homework.I have only two questions

1-If a diameter of a wire is doubled,what happens to its electicial resistivity?

2-Why is different the resistivity of materials?

Thanks

These questions arent that tough if take some time to look things up (such as the formula for electrical resistivity...)

**whistles** http://en.wikipedia.org/wiki/Resistivity

 

[cemx]

ok.I thought again and I understand the resistivity does not change.But I don't know any information about second question.I have looked wiki but I can't find any knowledge.Do you Help me

 

[xxChrisxx]

How do metals conduct electricity?

 

[NBAJam100]

ok.I thought again and I understand the resistivity does not change.But I don't know any information about second question.I have looked wiki but I can't find any knowledge.Do you Help me

Hmm... I think you still have some work to do on number one.

Look at the second equation down on the wiki page i posted

 

[xxChrisxx]

Yes and it shows that resistance will change, not resistivity which is a property of the materal.

:D

So assuming q1 is written down correctly, what he said is fine.

 

[cemx]

Yes and it shows that resistance will change, not resistivity which is a property of the materal.

I understand the second question.İt's different because every material have different R,r,l,A

Is it correct?

 

[xxChrisxx]

the question asks why the resistivity changes.

what you have stated does not show that.

btw are you talking about resistivity or resistance in the orig question? Just making sure you are answering the right q.

 

[cemx]

thank you so much brother I am really sure about it.My teacher gave me 100 points.Thank you again