Coil with current 2 A freely suspended on the inelastic thread in a uniform magnetic field. Period low torsional vibrations about the vertical axis with 1.2. The weight of the ring 3 Find the magnetic induction. Moment of inertia with respect to the coil axis, which coincides with its diameter is equal to J = mR2 / 2, where R - the radius of the coil.

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