Question

The magnetic field lines due to a bar magnet are correctly shown in
A.
B.
C.
D.

Answer 1

Hint:
In this problem we will use the concept of magnetism of a bar magnet and the magnetic field lines of the bar magnet. A bar magnet's field lines will move from its north pole to its south pole. Field lines that begin close to a pole's borders will hang around the bar magnet longer than field lines that begin closer to the pole's centre.



Complete step by step solution:
In a bar magnet, there are two poles named ‘North-Pole’ and ‘South-Pole’ such that the magnetic field lines originate from the North pole and end at the South pole outside the magnet.
But inside a magnet, the magnet field lines start from the South pole and end at the North pole. Since options (A) and (B) do not contain magnetic field lines inside a magnet that’s why options (A) and (B) are incorrect.
Now, option (C) has magnetic lines inside a magnet but in opposite direction i.e., from North to South which is wrong, therefore, option (C) is also incorrect.
Thus, the magnetic field lines due to a bar magnet are shown as: -

Hence, the correct option is (D).




Therefore, the correct option is D.




Note:
Since this is a problem related to a uniform magnetic field and magnetic lines of forces hence, it is essential that given options must be analyzed very carefully to give a precise explanation. While writing an explanation for this kind of conceptual problem, always keep in mind to provide the exact reasons in support of your explanation.