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Homework Statement
A very strong magnet is suspended by a non-magnetic thread. A student forms a loop out of a wire attached to the Pasco 750 Interface as shown on the left. During a half second interval, the student moves the wire loop until it is below the magnet as show
a) Describe (in enough detail) the resulting current versus time graph produced by the computer. If the current is non-zero at any time, could the current be the result of a magnet force on the positive charges in the wire? Explain.
Suppose that instead of the wire moving down, the magnet were pulled up. Assume that the magnet moves the same distance as the wire did, and in the same amount of time.
b) Describe (in enough detail) the resulting current versus time graph produced by the computer. If the current is non-zero at any time, could the current be the result of a magnet force on the positive charges in the wire? Explain.
Homework Equations
No equations; Conceptual
The Attempt at a Solution
for part (b) I've said:
As we saw in lab, it does not matter whether it is the magnet that moves, or the wire. It is the relative motion that induces the current. Thus, the current graph in this case, because the magnet moved the same distance as the wire in the same amount of time, and was pulled up (the wire was pulled down the magnet), the graph will be the same as in part a because their relative motion was the same.
Where I'm stumped is part a! I know that the magnetic field Inside the magnet points from south to north (so downwards), and I did the right hand rule assuming positive charge flows from red to black, and got the magnetic field induced in the wire to also be downwards. But I'm not sure what this means about the current graph of the wire (ie, when does it increase or decrease). I'm also not sure when/if it is ever 0?
Thanks for any help!