Question

Which of the following is true in case of a bar magnet and magnetic field lines produced around it?

• A. Magnetic field lines intersect each other at ${90}^o$ angles
• B. The tangent drawn at any point of a magnetic field line shows the direction of the magnetic field at that point
• C. The region in which the field lines are at a close distance has a weak magnetic field
• D. The magnetic field is a scalar quantity

Answer 1

Answer: (B)

Magnetic lines of force have a number of important properties, which include:

• They seek the path of least resistance between opposite magnetic poles. In a single bar magnet as shown to the right, they attempt to form closed loops from pole to pole.
  
• They never cross one another.
  
• They all have the same strength.
  
• Their density decreases (they spread out) when they move from an area of higher permeability to an area of lower permeability.
  
• Their density decreases with increasing distance from the poles.
  
• They are considered to have direction as if flowing, though no actual movement occurs.
  
• They flow from the south pole to the north pole within a material and north pole to south pole in air.
• The tangent drawn at any point of a magnetic field line shows the direction of the magnetic field at that point
  

So, B is correct.