The magnetic flux is given as
ϕ=A×B
ϕ=ABcos(ωt)
e=−Ndϕdt
e=−N×(sin(2πft))
At time t=0the emf will be zero because
sin(ωt)=0
As the time progresses the emf keeps on increasing.
A wire loop is placed in a region of time varying magnetic field which is oriented orthogonally to the plane of the loop as shown in the figure. The graph shows the magnetic field variation as the function of time. Assume the positive emf is the one which drives a current in the clockwise direction and seen by the observer in the direction of B. Which of the following graphs best represents the induced emf as a function of time.