Name the rule for finding the direction of magnetic field produced by a straight current-carrying conductor.

Maxwell's right-hand thumb rule is the rule for finding the direction of the magnetic field produced by a straight current-carrying conductor.

Extra information with the image is for reference only

According to Maxwell’s right-hand thumb rule, when a current-carrying conductor is held in the right hand so that our thumb points in the direction of the current, and the fingers that have wrapped the conductor gives the direction of the magnetic field lines around the wire.

When thumb points upwards, the wrapped fingers are anticlockwise. Hence, the direction of the magnetic field is anticlockwise. While when thumb points downwards, the wrapped fingers are clockwise. Hence, the direction of the magnetic field is clockwise.