Find magnetic field at point on Circumference/Ampere-Maxwell Eq. A uniform electric field points in the z direction with a value given by EZ(t) = a+bt, with a = 18 V/m and b = 2 V/(m s). The electric field is confined to a circular region in the xy plane with radius R = 4 meters. What is the magnitude of the magnetic field (in picoTesla) at a point P on the circumference of the circle at the time t = 2 seconds? After working with the Maxwell-Ampere equation I came down to this equation: B=[(Mo)(Eo)(dE/dt)(pi)(r^2)]/(2(pi)r)...which goes to [(Mo)(Eo)(r)(b)]/2...which goes to 4.4e-17 T or 4.4e-4 pT. It's wrong please help! Never mind figured it out!