A flat circular coil with 193 turns, a radius of 5.50 x 10-2 m, and a resistance of 0.241 Ω is exposed to an external magnetic field that is directed perpendicular to the plane of the coil. The magnitude of the external magnetic field is changing at a rate of ΔB/Δt = 0.908 T/s, thereby inducing a current in the coil. Find the magnitude of the magnetic field at the center of the coil that is produced by the induced current.
I did the following calculations, but still got the wrong answer. What am I doing wrong?
E=193(pi)(5.5E-2)^2(0.908)=1.6654
I=E/R=1.6654/0.241 ohms=6.9104 amps
B= (4pi E-7)(193) (6.9104) 2(5.5E-2)
B=1.8436 E-4