State a law, which determines the direction of magnetic field around a current carrying wire.

Right hand thumb rule determines the direction of magnetic field around a current carrying wire. It states that if we hold the current carrying conductor in right hand such that the thumb points in the direction of flow of current, then the fingers encircle the wire in the direction of the magnetic fields lines.

It is RIGHT HAND THUMB RULE which states “If we hold a current carrying conductor in the right hand such that thumb points in the direction of the current, the tips of fingers pointing the direction of magnetic field lines.”