A long straight wire is parallel to one edge of a rectangular loop as shown in figure-5.310. if the current in the long wire varies with time as `I=I_(0)e^(-tr)`, what will be the induced emf in the loop at t=`tau`?
A. `(mu_(0)bI)/(pitau)In((d+a)/(d))`
B. `(mu_(0)bI)/(2pitau)In((d+a)/(d))`
C. `(2mu_(0)bI)/(pitau)In("(d+a)/(d))`
D. `(mu_(0)bI)/(pitau)In((d)/(d+a))`