A rectangular loop in the x – z plane bounded by the lines x = 0, x = a, z = 0 and z = b is in a time varying magnetic field is given by B = B0 cosωt + ay. Where B0 is constant, ω is angular frequency and ay unit vector in the y direction. Now the emf induced in the loop is given by

• A.  ab Bo cosω t.
• B.  Bo ω sinω t.
• C.  Zero.
• D.   abω Bo sinω t.

Answer: (D)