A square loop of wire is held in a uniform $0\mathrm{.}24$ T magnetic field directed perpendicular to the plane ofthe loop. The length of each side of the square is decreasing at a constant rate of $5\mathrm{.}0$ cm$/$s$.$

a$)$ What is the magnetic flux in the loop when the length is $12$ cm$?$

b$)$ What emf is induced in the loop when the length is $12$ cm$?$