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#### Question

Two long coaxial insulated solenoids, S_{1} and S_{2} of equal lengths are wound one over the other as shown in the figure. A steady current "I" flow thought the inner solenoid S_{1} to the other end B, which is connected to the outer solenoid S_{2} through which the same current "I" flows in the opposite direction so as to come out at end A. If n_{1} and n_{2} are the number of turns per unit length, find the magnitude and direction of the net magnetic field at a point (i) inside on the axis and (ii) outside the combined system

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