[quote author=Fu-Kwun Hwang link=topic=915.msg5181#msg5181 date=1260583960]
Assume the width and height of the loop are d and h.
The magnetic flux in the loop is 
So the induced emf 
[/quote]
should be
is 
I check by sub t=0 , $\Psi =0.
The initial condition is causing the error in your equation. Right ?