Login

Welcome, Guest. Please login or register.

October 11, 2025, 03:22:09 am

Author Topic: Magnetic field strength vs magnetic flux density  (Read 1169 times)  Share 

0 Members and 1 Guest are viewing this topic.

Milkshake

  • Victorian
  • Trendsetter
  • **
  • Posts: 164
  • Respect: +1
Magnetic field strength vs magnetic flux density
« on: August 11, 2011, 06:03:20 pm »
0
Could someone please explain to me what the difference is between the two? I can't seem to find a clear explanation for it anywhere.

Thanks

#Sorry, it's magnetic field strength vs magnetic flux
« Last Edit: August 11, 2011, 06:07:19 pm by Milkshake »

Vincezor

  • Victorian
  • Forum Obsessive
  • ***
  • Posts: 332
  • Respect: +11
  • School: Glen Waverley Secondary College
  • School Grad Year: 2011
Re: Magnetic field strength vs magnetic flux density
« Reply #1 on: August 11, 2011, 06:14:38 pm »
+1
Magnetic Flux is the same as magnetic field density. It can be thought of as 'the number of field lines in a given area. It is measured in Webers (or Tm^2 or whatever)

Magnetic field strength refers to the magnitude in strength of the magnetic field. It is often denoted as 'B' and is in fact incorporated within the magnetic flux formula (Flux = BA)

Sorry if this doesn't really clear things up :( We just completed the electric power AOS so I'm in my 'Sound' mind set :P
2010: Systems Engineering 44            

2011: Specialist Mathematics 37 | Mathematical Methods (CAS) 43 | Physics 39 | Chemistry 42 | English 41

ATAR: 98.50

2012: Eng/Law @ Monash

Egregious Customer

  • Victorian
  • Adventurer
  • *
  • Posts: 5
  • Respect: 0
Re: Magnetic field strength vs magnetic flux density
« Reply #2 on: August 12, 2011, 12:04:15 am »
0
That really depends on what level of physics you are dealing with. Even physicists don't normally care too much about the difference, so we tend to use the terms interchangeably.

However, if you like, magnetic flux often refers to the B field. And yes, it is also called magnetic flux density. The word density should automatically tell you that we are dealing with a certain amount in a unit space (volume, area, etc.). In this case it is the area we are dealing with, hence the reason why total flux is equal to the magnetic flux density times the area it is passing through. Technically speaking, it is a dot product between the two, since both are vectors.

As for the magnetic field strength, you are now talking about the H field. We usually talk about the H field when dealing with materials. To put it in a simple picture, the field strength refers to how easy/hard it is for the magnet to alter the properties of said material. This is why we define


where is the magnetic permeability - a constant related to the properties of the material in question. I have ignored the magnetisation and so on, but they're irrelevant to the discussion.

tchung

  • Victorian
  • Adventurer
  • *
  • Posts: 15
  • Respect: 0
Re: Magnetic field strength vs magnetic flux density
« Reply #3 on: August 13, 2011, 11:12:25 pm »
0
That really depends on what level of physics you are dealing with. Even physicists don't normally care too much about the difference, so we tend to use the terms interchangeably.

However, if you like, magnetic flux often refers to the B field. And yes, it is also called magnetic flux density. The word density should automatically tell you that we are dealing with a certain amount in a unit space (volume, area, etc.). In this case it is the area we are dealing with, hence the reason why total flux is equal to the magnetic flux density times the area it is passing through. Technically speaking, it is a dot product between the two, since both are vectors.

As for the magnetic field strength, you are now talking about the H field. We usually talk about the H field when dealing with materials. To put it in a simple picture, the field strength refers to how easy/hard it is for the magnet to alter the properties of said material. This is why we define


where is the magnetic permeability - a constant related to the properties of the material in question. I have ignored the magnetisation and so on, but they're irrelevant to the discussion.

Dont you mean magnetic 'field' often refers to the B field.