A long straight wire of radius x carries a steady current I. The current is uniformly distributed across its cross section. Calculate the ratio of the magnetic field at \(\frac {x}{4}\) and 8x.

A long straight wire of radius x carries a steady current I. The curre

1.	A long straight wire of radius x carries a steady current I. The current is uniformly distributed across its cross section. Calculate the ratio of the magnetic field at \(\frac {x}{4}\) and 8x.
A.	4
B.	3
C.	2
D.	1
Answer» D.