A square wire loop with $1\mathrm{.}8$ m sides is perpendicular to a uniform magnetic field, with half the area of the loop in the field as shown in the figure. The loop contains an ideal battery with emf &$=18V.$ If the magnitude of the field varies with time according to $B=0\mathrm{.}050T-(0\mathrm{.}84\frac{T}{s})t,$ with $B$ in teslas and $t$ in seconds, what are

$($a$)$ the net emf in the circuit and

$($b$)$ the direction of the $($net$)$ current aro