There is a long vertical wire that carries a current in upward direction along y axis. A compass is placed near the wire on xz plane perpendicular to the wire. When there is no current in the wire, the compass neede points parallel to the north-south direction along z axis. Describe where the compass should be placed near the wire so that the needle is pointing directly to the cast when there is current in the wire. Explain your answer with the aid of a labelled simple sketch. Assume that the magnetic field which is created by the current carrying wire is much greater than the Earth's magnetic field.

There is a long vertical wire that carries a current in upward direction along y axis. A compass is placed near the wire on xz plane perpendicular to the wire. When there is no current in the wire, the compass neede points parallel to the north-south direction along z axis. Describe where the compass should be placed near the wire so that the needle is pointing directly to the cast when there is current in the wire. Explain your answer with the aid of a labelled simple sketch. Assume that the magnetic field which is created by the current carrying wire is much greater than the Earth's magnetic field.