| 1. | zero | 2. | \(\dfrac{\mu_{0} A K}{2 \pi l}\) |
| 3. | \(\dfrac{\mu_{0} A K}{ \pi l}\) | 4. | \(\dfrac{2 \mu_{0} A K}{\pi l}\) |
The diagram below shows two circular loops of wire (\(A\) and \(B\)) centered on and perpendicular to the \(x \)-axis and oriented with their planes parallel to each other. The \(y\)-axis passes vertically through the loop \(A\) (dashed line). There is a current \(I_{B}\) in the loop \(B\) as shown. Possible actions which we might perform on the loop \(A\) are:

| (I) | move \(A\) to the right along \(x \)-axis closer to \(B\) |
| (II) | move \(A\) to the left along \(x\)-axis away from \(B\) |
| (III) | as viewed from above, rotate \(A\) clockwise about the \(y\)-axis |
| (IV) | as viewed from above, rotate \(A\) anticlockwise about \(y\)-axis |
Which of these actions will induce a current in \(A\) only in the direction shown?
| 1. | (I) only | 2. | (II) only |
| 3. | (I) and (IV) only | 4. | (II) and (III) only |