Current induced in rotating conductor in Magnetic Field

  • Thread starter Jimmeh
  • Start date
  • #1
9
0

Homework Statement


attachment.php?attachmentid=18020&stc=1&d=1237310867.jpg



Homework Equations


[itex]l = 0.02 m[/itex]

[itex]r = 0.3 m[/itex]

[itex]E = \frac{-d\phi}{dt}[/itex]

[itex]\phi = BA[/itex]


The Attempt at a Solution


[itex]A = \pi 0.32^2 - \pi 0.3^2 = 0.0124\pi [/itex] .....Area "cut" by conductor

[itex]\phi = 1.5a_r0.0124\pi = 0.0186\pi a_r [/itex] ....change in flux in one revolution

[itex]1600 rev/min = 1600 rev/ 60 seconds = 1 rev / \frac{60}{1600} seconds[/itex]

[itex] E = \frac{-0.0186\pi a_r}{\frac{60}{1600}}[/itex]

[itex] E = -0.496\pi a_r V[/itex]

I'd just like someone to verify this please, and also I'm not sure about which end would be the anode. I think it'd be the end closest the origin, since the magnetic field is in the outward radial direction, [itex]a_r[/itex], the emf induced is in the [itex]-a_r[/itex] direction, and thus current would be flowing towards the origin, but I'm not sure if I went about handling the direction vectors the right way.
 

Attachments

Answers and Replies

  • #2
9
0
Anyone? The exam's tomorrow, I'd just like a quick verification....

Thanks
 
  • #3
Redbelly98
Staff Emeritus
Science Advisor
Homework Helper
Insights Author
12,121
159
It sounds like an inadequate description of the motion. 30 cm from the origin in what direction? And, what is the axis of rotation?

My hunch (without knowing the above information) is that the electric and magnetic forces on a test charge Q in the wire would have to be equal in magnitude, opposite in direction.
 

Related Threads on Current induced in rotating conductor in Magnetic Field

Replies
8
Views
6K
Replies
2
Views
3K
Replies
3
Views
246
  • Last Post
Replies
9
Views
2K
Replies
1
Views
15K
Replies
1
Views
578
  • Last Post
Replies
6
Views
538
Replies
1
Views
4K
Top