Suppose a room has a magnetic field, directed downwards. Then in order to experience the maximum magnetic force, the current carrying wire must be kept perpendicular to the magnetic field i.e horizontal to it.
True
The magnetic force on a current-carrying wire depends on the magnitude of current and the strength of the magnetic field. The force is maximum when the direction of current and the field are perpendicular to each other.
Since here, the direction of the magnetic field is acting downwards, the current carrying wire must be kept perpendicular to the magnetic field i.e horizontal to it.
Also, a point to be kept in mind is that this force is minimum (i.e. zero) if the current carrying wire and the field are along the same direction.