Why are magnetic field lines of a bar magnet always curved?

 

 

• The space around a magnet in which the force of attraction and repulsion due to the magnet can be detected is called the magnetic field.
• Magnetic lines of force are continous in naure which represent the region under the magnetic influence. 
• If a magnetic needle is placed in magnetic field of a bar magnet, it alligns itself in a definite direction. If the needle is displaced in the field, the direction of the needle continously changes. The path along whch the needle moves is a curved path which starts from the North pole and ends at the South pole of the bar magnet.This curved pat is called the magnetic field lines of force.
• It is one of the property of magnetic field lines that inside the magnet, the direction of field lines is from its south pole to its north pole.
• If we consider one line of force, then the strength of the magnetic field is same at all points on that magnetic field line. Also, a magnet does not have a monople. Its has two poles - North and South.
  Thus, the only possible path traced by the magnetic field lines so satisfy the above consitions is by having closed curves.