Two concentric circular loops, one of radius R and the other of radius 2R, lie in the xy-plane with the origin as their common center, as shown in the figure. The smaller loop carries current I₁ in the anti-clockwise direction and the larger loop carries current I₂ in the clockwise direction, with I₂ > 2I1. B⃗ (x, y) denotes the magnetic field at a point (x, y) in the xy-plane. Which of the following statement(s) is(are) correct?

Question

G1 Physics · Accepted Answer

For a circular current loop, at points in its own plane the field is normal to the plane. With concentric loops, rotational symmetry makes the magnitude depend only on radial distance r. Because the two loop contributions oppose, zeros can occur inside/among the loops, so C and D are not generally true. Hence A,B.