How Does Lenz's Law Determine Current Direction in Moving Loops and Magnets?

AI Thread Summary
Lenz's Law is applied to determine the direction of induced current in loops based on changes in magnetic fields. In the discussion, it is clarified that when the magnetic field weakens, the induced current flows clockwise, while it flows counterclockwise as the field strengthens. The participants agree that for the scenarios presented, options C, D, E, and F are correct, with specific attention to how the movement of loops and magnets affects the current direction. The importance of understanding the relationship between magnetic field strength and current direction is emphasized. Ultimately, the consensus is that CDEF are the correct answers to the problem posed.
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Homework Statement


The figures below show two different situations where a current may be induced in a loop according to Faraday's Law, with the direction given by Lenz' Law. The magnetic field is shown by the x's in Fig. 2. Select ALL correct answers (i.e. B, AC, BCD) for the current in the loop. (The compass directions are defined in the usual way.)

http://img517.imageshack.us/img517/9134/prob07lenzlaw1us4.gif
http://img67.imageshack.us/img67/2264/prob07lenzlaw2pi7.gif

A) fig2: Loop moving North, induced current `b'.
B) fig1: Magnet moving West, induced current `a'.
C) fig2: Loop moving South, no induced current.
D) fig1: Loop moving West, induced current `a'.
E) fig2: Loop moving East, induced current `b'.
F) fig1: Magnet moving East, induced current `a'.

In figure 2, the magnetic field is strongest on the left, weakest on the right. As the magnetic field gets weaker, the current will flow clockwise (b) as the magnetic field gets stronger the current travels counterclockwise (a). since the magnetic field is the same if you move up or down, this means that C and E are true. Using the same principle for figure 1, (as they get closer together, the current flows counterclockwise, as they move apart, the current flows clockwise. This means that CEF should be the answer... What am i missing?
 
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any insight into this one?
 
How do D & F differ? :wink:
 
jeez, why didnt i see that?:P So you would put your money on CDEF? i only have one attempt left at the question
 
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That's what I'd put.
 
Correct! Thanks
 
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