A wire experiences a force F F\,F at right angles to a uniform magnetic field. The length in the field is doubled and the magnetic flux density is reduced to one-third of its original value. What must happen to the current to keep the force equal to FFF?
It must become 3.03.03.0 times its original value.
It must become 0.670.670.67 times its original value.
It must become 6.06.06.0 times its original value.
It must become 1.51.51.5 times its original value.