Name the closed continuous curves which give the direction of force experienced by a magnetic material inside a magnetic field.

Magnetic Field lines are the closed continuous curves which give the direction of force experienced by a magnetic material inside a magnetic field.

Magnetic lines are concentric circles. The direction of magnetic lines gets reversed when the direction of current is reversed. 

When current flows in the upward direction, the direction of magnetic lines is anticlockwise. While, when current flows in the downward direction, the direction of magnetic lines is clockwise.