You cannot determine how much time it takes for magnetic line of forces to set up in space. It is not considered a real thing.
It can, but it can also determine a line in multi-dimensional (eg 3-d) space.
3 non-coplanar (pairwise) lines for 3 dimensional space.
magnetic field line is an imaginary line showing magnetic energy between a north and south pole .
You place the magnet under a piece of paper, and then sprinkle some iron filings on the paper. The iron filings will line up along the magnetic lines of force, which will show very clearly where the magnetic poles are.
Its magnetic domains line up.
Like any other object, they will travel in a straight line as long as no force pulls them sideways. Forces that might affect them (if present) include, in this case, gravity, as well as electric and magnetic fields.
A magnetic field line shows the direction a compass needle would point
You place the magnet under a piece of paper, and then sprinkle some iron filings on the paper. The iron filings will line up along the magnetic lines of force, which will show very clearly where the magnetic poles are.
2 points determine a line.
A magnetic field line shows the direction a compass needle would point.
A magnetic meridian is a line passing through a location connecting its magnetic north and south poles, while a geographical meridian is a line passing through a location connecting its geographic north and south poles. The magnetic meridian is affected by the Earth's magnetic field, while the geographical meridian is based on the Earth's rotation.
-- The product of the net charges on the two objects, the distance between their centers of net charge, and the nature of the material in the space between them, determine the magnitude of the electrostatic forces between them. -- The forces act along the line between the centers. Whether the forces point toward each other or away from each other depends on whether the net charges on the two objects have the same or opposite signs.