In a non-magnetic material, the graph of flux density (B) versus field strength (H) is:

B-H curve:

Definition:- The B-H curve is the characteristic representation of the magnetic properties of a material when placed in an external magnetic field.

For non-magnetic materials, B-H curve will not saturate. The curve will have a fixed slope approximately equal to µ₀. Therefore it will have a straight line passing through origin.

Note:-

• Diamagnetic materials have a slightly smaller slope.
• Paramagnetic materials have a slightly greater slope.

Important Points

• The residual magnetism or remanence or retentivity is the flux density that is left within the material after it has been magnetized.
• The coercivity is the magnetic field intensity that is required to demagnetize the material.
• The saturation effect of the material occurs when all of the magnetic domains within the material have aligned with the external magnetic field.
• This curve gives hysteresis losses in a transformer.