1. The problem statement, all variables and given/known data A rectangular loop of wire, of sides 5 and 3 cm moves away from a a long straight wire at 4ms-1 carrying a current of 2 amps. What is the EMF induced in the moving loop, when the near side of the loop is 3cm away from the wire? 2. Relevant equations B = μ0I/2πr EMF = -dΦ/dt 3. The attempt at a solution EMF = -dΦ/dt = -dAB/dt where A is the area, and B is the field. I am not sure what to do now as the answers I have seen treat A (the area) as changing? As I see it the area of the loop (A) is constant, and B changes as the loop moves out along the radius (the field gets weaker). Can anyone clarify which is right?