A thin long conductor of length L = 60 cm connected to a battery of emf ε = 12 V, and internal resistance r = 0.80 Ω carries a current I. The long conductor has resistance R = 5.0 Ω. The wires that connect the conductor to the battery have negligible resistance.
Consider the point P at a distance d = 5.0 cm.
(a) What is the direction of the magnetic field B created by the current I at point P?
(b) What is the magnitude of the magnetic field at P?
