Magnetic Field Lines

Permanent Magnet Magnetic Field Demonstrator
 
Magnetic Field Demonstrator is an ordered arrangement of 196 small iron rods that are free to rotate so that they can align themselves along the direction of the magnetic field (B), like a compass needle that shows you the direction of Earth's North Pole.

When the plastic box is moved around the pole of the magnet, we can observe the lines of magnet force. That lines of magnetic force are curved, and go from one pole of the magnet to the other pole. The outside lines are more curved than the ones near the poles.

WHAT TO DO:

What happens when you place the box above the two poles?
Answer: The ‘lines’ of the magnetic field are curved from one pole of the
magnet to the other. The outside lines are more curved than the ones near the
poles.

What is going on?

A magnet exerts a force at every point in space around it. The size
(magnitude) and direction of the force varies with position and distance
from the magnet. So in this case, the magnetic field of the magnet exerts a
force on the iron rods which causes them to align with the field.

There are no actual magnetic field ‘lines’ in the space, but one can draw lines
following the directions of the iron rods that show the direction of the force
at every point in space.

The magnetic field is an abstract idea that describes the space in the vicinity of the magnet. At every point in space the pole of a small magnet experiences a force which has a particular size and direction. There are no actual lines in the space, but one can draw lines that show the direction of the force at every point in space.

 

Magnetic Field Lines - Museum Booklet pdf

 

Physics Lecture Demonstration Database

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