Related to Magnetic field in a toroid

In a toroid the magnetic field lines run in concentric circle and are confined, while in a solenoid they run along the axis of solenoid and parallel to it, and final out of the solenoid opening at other end. It's not confined.

Another way to explain is this analogy. Just like a open pipe, we can't confine water, but we can if we join the two open ends together forming it in a shape of circle, i.e.  the toroid.

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TopperLearning.