An Electron Beam Travels Counterclockwise in a Circle in the Magnetic

question 105

Multiple Choice

An electron beam travels counterclockwise in a circle in the magnetic field produced by the Helmholtz coils, as shown. Assuming that Earth's field is downward, one can conclude that

• A) the Helmholtz field equals Earth's field.
• B) the current in the coils moves in the same direction as the electron beam.
• C) the current in the coils moves in the direction opposite to the electron beam.
• D) the Helmholtz field curves in the direction of the electron beam.
• E) the Helmholtz field curves in a direction opposite to the electron beam.