A uniformly charged ring with radius a = 10cm carries a total electric charge Q=3microCoulombs and rotates with angular speed w = 140rad/s counterclockwise about the z-axis. Find the magnetic field at the ring's center.
What is the magnitude of the magnetic field?
B =________ T
What is the direction of the magnetic field? (choose one)
-y
+x
+y
-z
+z