How Much Work is Done Moving a Charge in a Conducting Rod?

AI Thread Summary
The discussion centers on calculating the work done in moving a charge across a conducting rod with a given electrical potential. The equation used is delta U = q * V, leading to confusion about the sign of the work done. While the initial thought suggested that work should be negative due to moving from low to high potential, the correct interpretation is that the work done by an external force is positive, resulting in W = +neV. The question's ambiguity regarding whether it refers to work done by the electric field or by an external force is acknowledged. Clarification on the context of the work being asked is deemed necessary for accurate understanding.
heynkm1
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1.


If the electrical potential across a conducting metal rod of length L is V, how much work is done in moving a charge of +ne across the length of the rod, from low to high potential?


2.

Equation that I used: delta U = q * V



3.

This is what I thought: the charge moves from low to high potential, so the work done (by the electric field) has to be negative (so W = -neV). The answer was W = +neV.

Is my thought process incorrect, or should the question have been more specific and ask for exactly the work it was looking for (Work done by electric field or work done by external force)?
 
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Think about what units the eqaution WD=V*q would have then look at the answer you gave us :D
 
heynkm1 said:
This is what I thought: the charge moves from low to high potential, so the work done (by the electric field) has to be negative (so W = -neV). The answer was W = +neV.

Is my thought process incorrect, or should the question have been more specific and ask for exactly the work it was looking for (Work done by electric field or work done by external force)?
The presumption (tacit, unfortunately) of the question is: What work would need to be done by you (an external force) to move the charge (not the work done by the field, when the charge is moved).
 
OK, thank you for your help.
 
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