Mutual inductance of a coil inside a solenoid

  • Thread starter Amaelle
  • Start date
  • #1
Amaelle
310
54
Good day , i have an issue with the derivation of the mutual inductance of coil inside solenoid formula
inductance.png

I1 is an alternating current which means that B is varying, and we know that the Flux 21 is equal to the integral of the dot product of B and A2 but as B is varying we CAN NOT take it out of the integral and use the form used in the pic (the formula encercled in red).
Maybe there is something missing in my logic and any help would be highly appreciated, thanks!!!
 

Attachments

  • inductance.png
    inductance.png
    88.9 KB · Views: 2,999

Answers and Replies

  • #2
TSny
Homework Helper
Gold Member
13,660
3,843
You can take B out of the integral as long as B doesn’t vary with position.
 
  • #3
Amaelle
310
54
thank you for your prompt answer, but I still have difficulty to grasp this point, isn t B varying with time?? because the current is alternating? thanks!
 
  • #4
TSny
Homework Helper
Gold Member
13,660
3,843
Yes, B varies with time. So the flux varies with time. But the flux at any particular instant of time is a spatial integral of B over the surface A2. At any particular time, B is uniform over the A2.
 
  • #5
Amaelle
310
54
Thanks a million ! you nail it !!
 

Suggested for: Mutual inductance of a coil inside a solenoid

Replies
6
Views
804
Replies
0
Views
195
Replies
7
Views
809
  • Last Post
Replies
5
Views
450
  • Last Post
Replies
4
Views
331
  • Last Post
Replies
2
Views
351
Replies
13
Views
322
  • Last Post
Replies
1
Views
724
Replies
18
Views
301
Replies
41
Views
1K
Top