#### dinhjeffrey

1. Homework Statement

#32
2. Homework Equations

3. The Attempt at a Solution
umm i dont really understand this concept so heres my attempt. the answer is C so is it because if you have a wire within a wire and the current of one wire is going one direction, the current of the other wire always goes the opposite direction?

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#### AlexChandler

No that is not a good way to think about it. If the current in the outer wire were decreasing, then they would be going the same way. You have to think in terms of flux. Lenz's law says: "An induced current is always in such a direction as to oppose the motion or change causing it"

The cause of the induced current is the changing magnetic flux through the loop. The flux is increasing into the page, so the wire on the inside needs to produce a flux out of the page to resist the change.

If the wire on the outside had its current decreasing then there would be less flux into the page, so the inside wire would have to produce more flux into the page, and the currents would be in the same direction.

#### dinhjeffrey

thxthx i understand it now ^^

#### AlexChandler

thxthx i understand it now ^^
Good! Lenz's law is very cool. Check out this video on Lenz's Law.

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#### dinhjeffrey

oh cool my teacher showed us this in class too! lool

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