Note that the motion of the rod in the uniform magnetic field induces a current that circulates counter-clockwise. But the force on that current, in that moving rod in the magnetic field, is in the opposite direction to the velocity v, which means that unless we apply a force to keep the rod moving, and thus do work, the rod will come to rest and the current will go to zero. In the image at right, the change in B·A with time induces an emf and current (not shown) in the loop.