We have a circular non conducting ring placed in a uniform magnetic field with its direction perpendicular to the plane of the ring. There is a charge present on the ring. The field changes with a rate dB/dt. By lenz law we know that the ring will start rotating to form a current that will oppose change in B. But if we apply basic rules of physics - Where does this force required to move the ring come from? there is only magnetic field which cannot affect a rest charge.