• Support PF! Buy your school textbooks, materials and every day products via PF Here!

Magnetic field at centre and inside the toroid

  • Thread starter Saitama
  • Start date
3,810
92
1. Homework Statement
##N=2.5\times 10^3## wire turns are uniformly wound on a wooden toroidal core of a very small cross-section. A current ##I## flows through the wire. Find the ratio ##\eta## of the magnetic induction inside the core to that at the centre of the toroid.


2. Homework Equations



3. The Attempt at a Solution
The field inside the core has some finite value and at the centre it is zero. So the ration should be infinite but this wrong. I don't see what I have missed. :confused:
 
33,399
9,129
The toroid is like a second coil, the wire goes around it once.
 
3,810
92
The toroid is like a second coil, the wire goes around it once.
I still don't understand what you mean. :confused:
 

haruspex

Science Advisor
Homework Helper
Insights Author
Gold Member
2018 Award
31,721
4,690
mfb means that because the wooden core is very thin, when viewed from the centre, O, of the torus you can take the core as having zero thickness. This means that the toroid can be thought of as a simple loop of wire around O.
 
3,810
92
mfb means that because the wooden core is very thin, when viewed from the centre, O, of the torus you can take the core as having zero thickness. This means that the toroid can be thought of as a simple loop of wire around O.
The magnetic field inside the toroid is ##\mu_0NI/(2\pi R)## where ##R## is the radius of toroid.

Magnetic field at center of a loop is ##\mu_0NI/(2R)##. If I find the ratio ##\eta## using these two expressions, it comes out to be independent of N but this is wrong. :confused:
 
33,399
9,129
For the magnetic field at the center, you do not have N turns.
 

Want to reply to this thread?

"Magnetic field at centre and inside the toroid" You must log in or register to reply here.

Related Threads for: Magnetic field at centre and inside the toroid

  • Posted
Replies
3
Views
3K
Replies
0
Views
10K
  • Posted
Replies
6
Views
5K
  • Posted
Replies
2
Views
3K
  • Posted
Replies
1
Views
3K
Replies
2
Views
10K
  • Posted
Replies
3
Views
2K
Replies
6
Views
9K

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top