Calculate Resistance and resistivity

[Steelers72]

I have voltage, diameter, area, and inverse area data values. How could I calculate the resistance and resistivity with these numbers? I am pretty sure resistance is R=V/I and resistivity= RA/L , so I am not sure how I can calculate resistance without an I value.

 

[sophiecentaur]

I have voltage, diameter, area, and inverse area data values. How could I calculate the resistance and resistivity with these numbers? I am pretty sure resistance is R=V/I and resistivity= RA/L , so I am not sure how I can calculate resistance without an I value.

You are right. If you aren't told either R or both V and I, you cannot find resistivity. Are you trying to answer a Question in a book? Perhaps the current value is hidden somewhere else.

 

[Steelers72]

You are right. If you aren't told either R or both V and I, you cannot find resistivity. Are you trying to answer a Question in a book? Perhaps the current value is hidden somewhere else.

Im not sure. It was a lab. Very frustrating because current is mentioned anywhere

 

[alw34]

inverse area data values.

What is that?

You have the right formulas, not sure you have the data.

For example, for resistivity there are four values...to calculate a fourth, you need the three others...

https://en.wikipedia.org/wiki/Electrical_resistivity_and_conductivity

edit: Sophie posted while I was composing.

 

[sophiecentaur]

Yes: frustrating if you can't go back and do it again. It can be difficult if you are working to a set of instructions which are presented in steps but without the necessary background. I don't know where you can go from here to get an actual result - but you have sussed out the theory now so everything isn't lost.

 

[alw34]

It was a lab

Tip for labs:
Before any lab, always know what your outputs, that is results, should be. Know what you are looking for.

Then you determine before the lab what measurements, what variables, are required during the lab.

 

[Steelers72]

Thanks for the advice. I wish there was a manual it is all written in paragraph form. Annoying.

 

[sophiecentaur]

Tip for labs:
Before any lab, always know what your outputs, that is results, should be. Know what you are looking for.

Then you determine before the lab what measurements, what variables, are required during the lab.

Absolutely. Just following your nose through a series of measurements can often lead you nowhere. Despite the 'learning by doing' mantra that's practiced in many places, getting to know the theory first is much more reliable.

 

[sophiecentaur]

Thanks for the advice. I wish there was a manual it is all written in paragraph form. Annoying.

The theory isn't in manuals - it's in textbooks, which have probably been better thought out than a set of lab instructions.

 

[alw34]

if you can't go back and do it again.

good point. If you had lab partners and they recorded what you need get it. Otherwise go back to the lab instructor explain your problem and do it over. I taught EE labs as a grad student and several times people came back to do some additional work...no big deal.