Designing a simple magnetic field gen with a straight wire. Need current density

AI Thread Summary
The discussion focuses on designing a magnetic field generator using a solid metal wire with a specified radius of 2mm. The goal is to achieve a magnetic field of 7.5 x 10^-13 Tesla at a distance of 8mm from the wire's axis, utilizing Ampere's Law for derivation. The current density, J, is defined as J = I/(π*r^2), where I is the current flowing through the wire. Participants are attempting to visualize the problem through diagrams, but there are concerns about their accuracy. The conversation emphasizes the need for a clear understanding of the equations involved in calculating current density and magnetic fields.
ARBY1
Messages
2
Reaction score
0

Homework Statement


Need to design a simple magnetic field generator of radius a= 2mm. The solid metal wire must carry a current density, jw, uniformly distributed over its cross section. The current density that must be found must have a magnetic field at a radial distance of r= 8mm from the axis of the wire is 7.5 10^-13 Tesla. Ignore end effects. Must develop the equation using Ampere's Law as the beginning derivation.


Homework Equations


I=∫J*da
A=r*r*∏
B∫J*ds

The Attempt at a Solution



I am have been trying to start off this by drawing a diagram but I don't even think it is correct.

http://imageshack.us/photo/my-images/440/finalprep.png/
 
Physics news on Phys.org
Also I forgot an equation jw inside is

J=(I)/(∏*r*r)
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Calculating Magnetic Field at Point P for Perpendicular Current-Carrying Wires
Replies
2
Views
1K
Why is magnetic field B along a straight wire circular not radial?
Replies
14
Views
3K
Finding magnetic field using Ampere's Circuital Law
Replies
5
Views
992
EM fields and Current between 2 charged cylinders
Replies
10
Views
2K
Magnetic field generated by a current in a wire - special relativity
Replies
1
Views
2K
Magnetic field due to infinite current carrying wire in the X and Y axes
Replies
11
Views
3K
Magnetic field due to the current flowing in a bent wire
Replies
1
Views
2K
Does a Bent Wire Affect Induction Calculations?
Replies
7
Views
2K
How Does a Magnetic Field Affect a Wire Carrying Current?
Replies
2
Views
1K
Find direction of current in a magnetic field
Replies
34
Views
3K

Hot Threads

Recent Insights

Back
Top