Problem: A fixed loop with Radius a and Resistance R is parrallel with the y-z plane. Another loop with radius r parallel to the y-z plane and a distance away from the other loop has a velocity v moving toward the other loop. What is the induced Voltage? Assuming (Told to assume this) a << r << x (Distance between loops) B = (UIr^2) / (2x^3) <--- Taken from physics book Flux = Integral B * n dA = Bpiea^2. (Flux thru fixed loop) Voltage = d(Flux)/dt = -piea^2d(B)dt = -(piea^2UIr^2)/2 d(1/x^3)/dt Problem... d(1/x^3)/dt = -3x^-4*v... I wasnt given x so how do I solve this? Voltage = (pie*a^2*U*I*r^2*3x^-4*v)/2 (I'm not given I or x) What am I doing wrong here.