# What is change in the magnetic flux (delta B)?

1. Jan 13, 2008

### Physicsissuef

What is change in the magnetic flux (delta B)? Like on this http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/emfchb.html" [Broken]

Last edited by a moderator: May 3, 2017
2. Jan 13, 2008

### rock.freak667

Well the magnetic flux is given by $\Phi=BA$ where B is magnetic flux density and A is the surface area.
So a field interacts with another magnetic field then the value of B changes and hence there should be a rate of change of flux. And by faraday's law, and emf is induced.

3. Jan 14, 2008

### Physicsissuef

Is it like, when I approach magnet, than the magnetic domains of the coil get in line with the magnetic field of the magnet and when I get back the magnet, the magnetic domains of the coil are like in the first position? I mean, for the direction of the magnetic flux.

Last edited: Jan 14, 2008
4. Jan 14, 2008

### Physicsissuef

Can somebody help me to determine the direction of the magnetic flux of the coil?is that, something to do with the aligning of the magnetic domains?

5. Jan 14, 2008

### rock.freak667

A coil like a solenoid? if so then to determine the direction of the magnetic flux you need to use the right hand grip rule

6. Jan 14, 2008

### Physicsissuef

But, I thought in practical way. What happens with the flux?

7. Jan 15, 2008

### Physicsissuef

And can you please explain me this quote from "Newton Ask A scientist"
How is it possible that increasing the amount of air will change the direction of the beads?
Here is the whole topic: