- #1
lillybeans
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Homework Statement
A coil with zero resistance has its ends labeled a and b. The potential at a is higher than at b. Explain why the two following statements are consistent/correct with the situation.
a) The current is increasing and is directed from a to b.
b) The current is decreasing and is directed from b to a.
The Attempt at a Solution
The reason why I am confused is because I thought:
1. If the current is increasing from a to b, then the EMF induced should want to produce a current from b to a (opposite to the original direction of the current). In order to produce a current from b to a, you need the voltage at b to be higher potential than a, not a at a higher potential than b. So I don't see how the first statement is consistent with the situation.
2. A similar problem. If the current is decreasing and is directed from b to a, then the EMF induced would try to INCREASE/reinforce the current from b to a. That would still require b at a higher potential than a,not a at a higher potential than b as the problem suggested.
I'm quite sure I am misunderstanding something here, but I don't understand why my reasoning is wrong and why the textbook's reasoning is right. Please help!
Thanks.