$(a)$ Describe an activity to draw a magnetic field line outside a bar magnet from one pole to another.
$(b)$ List any two properties of magnetic field lines.

(N/A) Place the bar magnet $NS$ on a sheet of paper and mark its boundary. Mark a point $A$ near the north pole of the magnet. Place a compass needle such that its south pole lies exactly over point $A$. Mark point $B$ on the paper at the position of the north pole of the compass needle. Move the compass needle so that its south pole now lies over $B$ and mark point $C$ at the north pole position. Repeat this process until you reach the south pole of the bar magnet. Join all these points with a smooth curve to represent a magnetic field line.
$(b)$ $(i)$ Magnetic field lines never intersect each other.
$(ii)$ Outside the magnet,magnetic field lines emerge from the north pole and merge into the south pole.