Question
A rectangular loop and a circular loop are moving out of a same magnetic field to a field free region with constant velocity.

It is given that the field is normal to the plane of both the loops. Draw the expected shape of the graphs. Showing the variation of flux with time in both the cases. What is the cause of the difference in the shape of the two graphs?
Solution

In case of a rectangular loop, the rate of change of area is uniform. Hence, induced emf will be constant as the loop moves out of the magnetic field.
When, a circular loop is moved out of the magnetic field, the rate of change of area is not constant and hence, the induced emf produced will not be constant.