A planar loop of wire rotates in a uniform magnetic field. Initially, at t=0 , the plane of the loop is perpendicular to the magnetic field. If it rotates with a period of 10 s about an axis in its plane then the magnitude of induced emf will be maximum and minimum, respectively at:
a. 2.5 s and 7.5 s
b. 2.5 s and 5.0 s
c. 5.0 s and 7.5 s
d. 5.0 s and 10.0 s