As shown in the figure, a long straight conductor with semicircular arc of radius π/10 m is carrying current I = 3A. The magnitude of the magnetic field. at the center O of the arc is: (The permeability of the vacuum = 4π × 10–7 NA–2)
(1) 6µT
(2) 1µT
(3) 4µT
(4) 3µT
