Physics

Problem

Two coplanar, concentric circular loops have radii

R

and

2R

. The smaller loop carries a clockwise current of

5\,\text{A}

. What current must flow in the larger loop so that the net magnetic field at their common centre is zero? a)

2.5\,\text{A}

anticlockwise b)

20\,\text{A}

anticlockwise c)

10\,\text{A}

anticlockwise d)

10\,\text{A}

clockwise