Asquare wire loop of side l and resistance r is pulled with constant speed v from a region of no magnetic field until it is fully inside a region of constant, uniform magnetic field b⃗ perpendicular to the loop plane. the boundary of the field region is parallel to one side of the loop. find an expression for the total work done by the agent pulling the loop. express your answer in terms of the variables b, l, v and r. w=