1. Electro-Magnetic Induction
© D Hoult 2008

2. Magnetic flux

6. If the magnitude of the flux density is B then the magnitude of the magnetic flux (f) linked with the area A is defined to be

7. If the magnitude of the flux density is B then the magnitude of the magnetic flux (f) linked with the area A is defined to be
f = A B

8. f = A B
units of flux

9. f = A B
units of flux T m2

10. f = A B
units of flux T m2
1 T m2 = 1 Weber (Wb)

12. Now, the magnitude of the component of the flux density perpendicular to the area is B cos q

13. so the magnetic flux (f) linked with the area is now
Now, the magnitude of the component of the flux density perpendicular to the area is B cos q
so the magnetic flux (f) linked with the area is now
f = A B cos q
alternatively

14. In practice, the area in question is usually surrounded by a conductor, often a coil of wire.

15. In practice, the area in question is usually surrounded by a conductor, often a coil of wire.
If the coil of wire has N turns, we define the flux linkage as follows

16. In practice, the area in question is usually surrounded by a conductor, often a coil of wire.
If the coil of wire has N turns, we define the flux linkage as follows
Flux linkage = N f