## jennychan12 2 years ago Circuits: A certain material has a voltage of 120 V across 10 A and the length of the wire is 25 m, while the diameter is 5 mm. What it its resistivity?

1. jennychan12

$V = IR$ $P = IV$ $R = \frac{ \delta L }{ A }$ i used the first one (R=V/I) is that right?

2. jennychan12

and you're not given the constant.

3. modphysnoob

so first find the resistance

4. jennychan12

yeah i got that 12 ohms

5. jennychan12

using the first formula right?

6. modphysnoob

yes

7. jennychan12

that's it? but what are the length and diameter given for?

8. modphysnoob

once you find R , use that and given diameter and length to find resistivity which is $\delta$

9. jennychan12

-_- grr. i thought the R was the resistivity.. fdjsalkfhdjkshfklhg got that question wrong on the quiz >:(

10. jennychan12

thanks tho. :)

11. modphysnoob

R is resistance

12. jennychan12

oh okay. my teacher didn't explain clearly. :(

13. modphysnoob