Two parallel wires \(AL\) and \(BM\), placed at a distance \(l\), are connected by a resistor \(R\) and placed in a magnetic field \(B\) perpendicular to the plane of the wires. Another wire \(CD\) connects the two wires perpendicularly and is made to slide with velocity \(v\). Neglect the resistance of all the wires. What is the work done per second needed to slide the wire \(CD\)?