A current carrying ring of radius r, carrying a current i, is placed in the uniform magnetic field of induction B→ directed into the plane of the ring, as shown in the figure. Then

Each small element of the ring experiences a radially outward force (∆F→=i∆l→ x B→). As a result a tensile force is induced in the wire. Net force ∑ ∆F→ on the ring is zero. Angle between magnetic dipole moment M→ and magnetic field B→ is zero. Hence net torque (τ=MBsin0o) is zero.