A conducting loop is pulled with a constant velocity towards a region of constant (steady) magnetic field d induction B as shown in the figure. Then, the current involved in the loop is (d > r)
When the loop is drawn into the magnetic field, the area of the portion of the loop in the magnetic field will increase. That means, the flux linkage increases. Therefore, an (anti-clockwise) emf is induced in the loop, so as to oppose the change, that is to say to oppose the increase in magnetic flux in the loop. Therefore, the current will have to induce in anti-clockwise direction to induce an opposing magnetic field, that is pointing outward of the page. After the complete enter of the loop into the magnetic field, no variation of flux occurs. Therefore, it induces no current so long as the loop is completely inside the magnetic field. When it emerges out of the magnetic field, following the previous argument, the direction of induced in it will be reversed (clockwise).