An decreasing current I flows in an elliptical loop of wire. Two loops of wire a
ID: 776493 • Letter: A
Question
An decreasing current I flows in an elliptical loop of wire. Two loops of wire are placed as shown. Why is the flow of induced current counterclockwise for loop 1? I thought that mutually induced emf equals (-)M(di/dt). Doesn't the negative sign mean that the mutually induced emf (and hence the induced current) will be in the opposite direction of the rate of change of current? So why wouldn't the induced current for loop 1 be clockwise?
ALSO: what is the reasoning for why loop 2's induced current is clockwise?
Explanation / Answer
For loop 1, since the current is decreasing field in outwards will decrease. So to maintain flux, we need more field in the same direction(outward). That's the reason loop 1's field should be outwards means current to be counterclockwise.
For loop 2, over loop 2 net field due to elliptical loop is inwards because the closest part of the elliptical wire to loop 2 is having current upward. And with the similar logic of maintaining flux, loop 2 needs to give field inwards to support flux which is decreasing with decreasing current. So field od loop 2 should be inwards means clockwise induced current.
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