$(6$ points$)$ Consider the conducting loop in a magnetic field $B=2\mathrm{.}0$That$(z)$ as shown. If the loop's radius is decreased from $r_1=0\mathrm{.}5m$ to $r_2=0\mathrm{.}1m$ in $2\mathrm{.}0$ seconds, calculate the magnitude and the direction of the induced emf in the loop. Express $+$ or $-$ for counterclockwise or clockwise respectively.