physics practice question

[jjoe00]

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A 21,000 V transmission line has resistance of 3.3 10-4 Ω per meter of length and carries a current of 39 A.
(a) Find the potential difference of points 1.1 m apart on one wire.

(b) What is the potential difference between the two adjacent wires?


what formula do i use ? thanks!

 

[MDub1]

For the first one, you simply need to use V=IR. R in this question would be (3.3 * 10-4 Ω/m)(1.1 m). I think I'm missing something on the second one. Does it give you the length of the entire line?

 

[Morsetlis]

b.) should be 0 V. You have no points of reference, so the only possible answers are 0 V or 21kV.