Magnetism: magnetic feild strength of a wire

  • #1
physicsStudent00

Homework Statement



A wire 1.0 mm in diameter carries 5.0 A distributed uniformly over its cross section.

a) Find the field strength 0.10 mm from its axis.

b) Find the field strength at the wire’s surface

Homework Equations




The Attempt at a Solution


I've used the Biot-Savart Law for a wire for both of the questions and had the wrong answer both times. Using the wire law: B=(μ_0)(I)/2πr
a) B=(μ_0)(5)/2π((1+0.1)*10^-3) = 9.091*10^-4
b) uses the same approach

i don't understand what numbers to be using or if I'm using the wrong equation's here?
any help is much appreciated
 
  • Like
Likes ISamson

Answers and Replies

  • #2
BvU
Science Advisor
Homework Helper
2019 Award
13,703
3,341
a) asks for 0.1 mm from its axis, not from its surface
 
  • #3
physicsStudent00
a) asks for 0.1 mm from its axis, not from its surface
by taking the radius as 0.1*10^-3 it gives 0.01T which still is wrong
 
  • #4
BvU
Science Advisor
Homework Helper
2019 Award
13,703
3,341
How much current is within this ##10^{-4}## m radius ?

In other words: does your
Using the wire law: B=(μ_0)(I)/2πr
apply inside the wire ?
 
Last edited:

Related Threads on Magnetism: magnetic feild strength of a wire

  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
1
Views
824
  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
10
Views
3K
Replies
3
Views
5K
  • Last Post
Replies
2
Views
949
  • Last Post
Replies
6
Views
570
  • Last Post
Replies
10
Views
2K
  • Last Post
Replies
2
Views
4K
Top