A square coil ACDE with its plane vertical is released from rest in a horizontal uniform magnetic field E of length 2L (figure). The acceleration of the coil is

When the coil is within the field, there is no change in the magnetic flux passing through it. Thus, no current will be induced and the acceleration will be g. But according to Lenz's law, the induced current will oppose its motion when it enters or leaves the field. Therefore, acceleration will be less than g.