Question

What is a magnetic field strength?

Answer 1

Magnetic field strength, often denoted as "H," is a measure of the intensity or strength of a magnetic field in a given region of space. It is a fundamental concept in electromagnetism and describes the magnetic force experienced by a magnetic material placed within the field. Magnetic field strength is distinct from magnetic flux density (often denoted as "B"), which is a measure of the actual magnetic field at a specific point in space.

The magnetic field strength, H, is related to the magnetizing current that generates the magnetic field in a material. In other words, it quantifies the amount of magnetizing force applied to a unit length of the material. It's an important parameter in determining how a magnetic field affects materials with magnetic properties, such as ferromagnetic materials like iron.

The relationship between magnetic field strength (H) and magnetic flux density (B) is given by:

B = μ₀(H + M),

where:

B is the magnetic flux density (measured in teslas, T).
H is the magnetic field strength (measured in amperes per meter, A/m).
M is the magnetization of the material (magnetic moment per unit volume).
μ₀ (mu naught) is the permeability of free space, a constant that relates the two.

In summary, magnetic field strength represents the applied magnetizing force, while magnetic flux density represents the resulting magnetic field that this force generates in a specific material.