An electron is launched with velocity v in a uniform magnetic field b. the angle θ between v and b is between 0 and 90°. as a result, the electron follows a helical path. the pitch of the helix is defined as: a) the angle the helix makes with the magnetic field. b) the angle the helix makes with the electron's velocity vector. c) the radius of the circular motion. d) the distance between adjacent turns of the helix. e) the time it takes the electron to move from one turn on the helix to the next. explain !