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

Am I on the right track with Ampere's Law?

  • Thread starter jumbogala
  • Start date
1. Homework Statement
A wire carries a current of 3 A in the downward direction. What is the magnetic field 2.0 cm away from the wire?


2. Homework Equations
∫B·dl = µ0I


3. The Attempt at a Solution
So I pick a circle with radius 2.0 cm to go around the wire, and get

B∫dl = µ0(3 A)

∫dl evaluates to 2pi(0.02 m).

So B = [µ0(3 A) ] / 2*pi*0.02 m?
 
That works, however the Biot-Savart law is easier to apply here and actually reduces to a formula identical to what you have written in the last line in the case of a long straight wire. B=µ0I/2(pi)r
 
Thank you! I know the Biot-Savart law also works, I just wanted to make sure my concept of Ampere's Law was correct. =)
 

Related Threads for: Am I on the right track with Ampere's Law?

  • Posted
Replies
3
Views
2K
  • Posted
2
Replies
25
Views
4K
Replies
1
Views
939
Replies
5
Views
934

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