Why does a magnetic compass needle pointing North and South in the absence of a nearby magnet get deflected when a bar magnet or a current-carrying loop is brought near it. Describe some silent features of magnetic lines of field concept.

Explanation

When a magnetic compass needle pointing north and south in the absence of a nearly magnet or a current loop, it is action upon by the earth's magnetic field only. But in the presence of a magnet or a current loop (which also has a magentic field ) the earth's magnetic field near to compass is modified and the needle is deflected from north and south directions.
(i) A magnetic field line is directed from north-pole to south -pole outside the magnet. ltbr (ii) A magnetic field line a closed and continuous curve
(iii) The magnetic field lines never intresect each other, because if two line meet, means that force is acting in two directions at that point which is not possible.
(iv) Closer the field , stronger is the magnetic field and vice-vers is also true.
(v) Magnetic field line are parllel and equdistant, those represent a uniform magnetic field.