Physics--- electricity and magnetism?

A flat, round iron ring 5.80cm in diameter has a current running through it that produces a magnetic field of 76.0*10^-6T at its center. This ring is placed in a uniform external magnetic field of 0.360T . A) What is the maximum torque the external field can exert on the ring? (in N*m) ?max B) How should the... show more A flat, round iron ring 5.80cm in diameter has a current running through it that produces a magnetic field of 76.0*10^-6T at its center. This ring is placed in a uniform external magnetic field of 0.360T .

A) What is the maximum torque the external field can exert on the ring? (in N*m)

?max

B) How should the ring be oriented relative to the field for the torque to have its maximum value?

a. the plane of the ring should be parallel to the field

b. the plane of the ring should be normal to the field
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