posted by Jessica .
If you have a rectangular loop of area A placed in a region where the magnetic field is perpendicular to the plane of the loop, than would the emf be zero because they are perpendicular?
First the field through the loop must be changing with time to generate voltage around the loop.
If the B field vector lies in the plane of the loop, there is no flux through the loop. However if the field is changing or equivalently the loop is rotating, there is a rate of change of magnetic field flux through the loop and an emf appears.