B(r) r R The cross-section of a long thick wire of ra- dius R is shown above. It carries a current I into the page. We would like to determine magnetic field B(r), outside the wire, a dis- tance r from the center of the wire, where r > R, and is near the midpoint of the wire where the end effect at both ends are negligi- ble. We solve this problem based on Ampere's Law. The left hand side of Ampere's law is given by:Ia) 27 RB(r) Ib) 2TT B(r) The right hand side of Ampere's law is: Ila) poll IIb) poll R2 The field B(r) at r is given by: IIIa) Holl Hol1 R2 IIIb) 2TT