- #1
Abdulwahab Hajar
- 56
- 2
Homework Statement
The general method to find the total magnetic flux through an object is found by:
Φ =∫B*ds (dot product)
what is the ds over which we take the integral on??
what surface is it?, is it the surface over which the magnetic flux enters?
Homework Equations
Φ =∫B*ds (dot product)
The Attempt at a Solution
well the problem is that a magnetic field can extend so far right??
but in a toroid we assume that almost B= 0 anywhere other than in between the inner and outer radius.
Therefore the surface should be one in between the inner and outer radii of the toroid, in a toroid like the in the figure attached the magnetic field is µ0NI/2πr
therefore the total flux Φ =∫(µ0NI/2πr)*ds
In the book ds is defined as h*dr (in the direction of phi)
why can't ds simply be h*(b-a) namely the height of the toroid multiplied by the outer radius - the inner radius
why is the term dr necessary??
furthermore what is ds usually in general?
Thank you