r should be in metres - having gone back and checked I realized that I should actually have had an extra 0 in there and it should have been 0.01 m. I should probably check my values better as I seem to often have problems with this!
Thanks for your help.
Homework Statement
Assume that I = 5.0A.
What is the magnetic field at point b in the figure? Give your answer as a vector.
Homework Equations
Ampere's Law - B = (μ0I)/(2πr)
The Attempt at a Solution
I tried plugging the given numbers into Ampere's Law for point b, which gave me B =...