A uniform electric field e exists between the plates a and b and a uniform magnetic field b exists between plates c and d. A rectangular coil X moves with a constant speed between AB and CD with its plane parallel to the plates. An emf is induced in the coil when it
(a) Enters and leaves CD
(b) Enters and leaves AB
(c) Enters and leaves both AB and CD
(d) Moves completely with CD
Answer: (a) Enters and leaves CD