EMF v time graph vs change in flux v time

  • Thread starter alv
  • Start date
  • #1
alv
6
0
I'm actually a teacher and I can't explain this problem from the 2007 HSC. I've attached a copy of the question and the two graphs. The question shows a graph of change in magnetic flux vs time and asks you to choose which graph of induced emf best fits it. I don't understand why the induced emf is at max even while the change in flux increases (or decreases).

I've searched for help on this but can't find it. I'd appreciate any explanation you could give me.

Thanks

Homework Statement


Please see above


Homework Equations


Please see above


The Attempt at a Solution


Please see above

Homework Statement





Homework Equations





The Attempt at a Solution

 

Attachments

  • For physics forums.png
    For physics forums.png
    12.8 KB · Views: 12,484

Answers and Replies

  • #2
ehild
Homework Helper
15,543
1,912
emf= -ΔΦ/Δt, more accurately, the negative of the time derivative of the flux. The magnitude of the emf is maximum when the flux-time graph is steepest. ΔΦ is the change of the flux in time interval Δt.
As the graph consists of linear segments, the emf is constant within one segment. The vertical lines do not mean anything.
ehild
 
  • #3
1,065
10
Actually there's no maximum or minimum value. Just polarity change due to changes in gradient.Normally verticall line is dotted.
 
  • #4
alv
6
0
Thanks heaps for this.
 

Related Threads on EMF v time graph vs change in flux v time

  • Last Post
Replies
4
Views
3K
Replies
8
Views
74K
Replies
2
Views
6K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
2
Views
2K
Replies
7
Views
3K
  • Last Post
Replies
5
Views
22K
Replies
1
Views
7K
  • Last Post
Replies
4
Views
3K
Top