A toroid has 200 turns of wire with a current of 3 A passing through the wire.The inner radius of the toroid is 3 cm and the outer radius is 5 cm.Calculate the magnetic field strength at a radius of 2 cm. A)6.0 $\times$ 10^-3 T B)3.0 $\times$ 10^-3 T C)1.2 $\times$ 10^-2 T D)4.8 $\times$ 10^-4 T E)none of the above

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Quizplus · Accepted Answer

The magnetic field inside a toroid is given by the formula $B = \frac{\mu_0 N I}{2\pi r}$, where $N$ is the number of turns, $I$ is the current, and $r$ is the radius from the center of the toroid. However, this formula only applies to points within the toroid itself (i.e., for radii between the inner and outer radii of the toroid). Since the radius given (2 cm) is less than the inner radius of the toroid (3 cm), the point in question lies outside the region where the toroidal magnetic field exists. In such a case, the magnetic field strength is effectively zero because the magnetic field lines inside a perfect toroid are contained within the body of the toroid and do not extend outside it. Therefore, none of the given options correctly describe the magnetic field strength at a radius of 2 cm.

A Toroid Has 200 Turns of Wire with a Current ×\times×

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