Question

A rectangular, a square, a circular and an elliptical loop, all in the $xy$ plane, are moving out of a uniform magnetic field with a constant velocity $\overrightarrow{V}=v\hat{i}$. The magnetic field is directed along the negative $z$ axis direction. When the loops are drawn out of the region of magnetic field, the induced emf will not remain constant in

• A. the circular and the elliptical loops
• B. only the elliptical loop
• C. any of the four loops
• D. the rectangular, circular and elliptical loops
  

Answer 1

Correct option is (A): the circular and the elliptical loops
When the loops are being drawn out of the field, the rate at which the number of field lines cutting through the loop decreases will be a constant for square and rectangle loops, but not for circular or elliptical shapes.