Starting Outside the Region with the Magnetic Field,a Single Square $\vec { B }$

Multiple Choice

Starting outside the region with the magnetic field,a single square coil of wire moves across the region with a uniform magnetic field $\vec { B }$ perpendicular to the page.The loop moves at constant velocity $\overrightarrow { \mathbf { v } }$ .As seen from above,a counterclockwise emf is regarded as positive.Roger claims that the graph shown below represents the induced emf.Martin says he's wrong.In which direction did the loop move over the plane of the page,or is Martin correct?

A) Roger is correct: the loop moved from bottom to top.
B) Roger is correct: the loop moved from top to bottom.
C) Roger is correct: the loop moved from left to right.
D) Roger is correct: the loop moved from right to left.
E) Martin is correct: none of these directions of motion will produce the graph of emf vs t.