Confused about resistance

  • #1

Homework Statement


A cylindrical copper rod of length L and cross-sectional area A is re-formed to
twice its original length with no change in volume. If the resistance between its
ends was originally R, what is it now?


Homework Equations


R=p(L/A)


The Attempt at a Solution


Using the above equation the answer would be 2R, however the correct answer is 4R. Why is this? I am studying for a test tomorrow and need to understand why this is so.
 

Answers and Replies

  • #2
44
0
If it has the same volume but twice the length, what will happen to the cross-sectional area?
 
  • #3
If it has the same volume but twice the length, what will happen to the cross-sectional area?

ahhh, it will be 1/2 of the original, thanks.
 

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