Magnetic Field Strength (H)

Magnetic Field Strength (H)

 • This gives quantitative measure of strongness or weakness of the magnetic field. Note that pole strength and magnetic field strength are different. This can be defined as 'The force experienced by a unit N-pole (i.e. N pole with 1 Wb of pole strength) when placed at any point in a magnetic field is known as magnetic field strength at that point.

• It is denoted by H and its unit is newtons per weber i.e. (N/Wb) or amperes per metre (A/m.) or ampere turns per metre (AT/m). The mathematical expression for calculating magnetic field strength is,

H =  Ampere turns/Length

ஃ   H = NI/l  AT/m

Key Point : More the value of 'H', more stronger is the magnetic field. This is also called magnetic field intensity.

Review Question    

1. Define magnetic field strength and state its units.