7. An electron is moving directly toward you in a horizontal path when it suddenly enters a uniform magnetic field that is either vertical or horizontal. If the electron begins to curve upward in its motion just after it enters the field, you can conclude that the direction of the magnetic field is A. upward. B. downward. C. to your left. D. to your right. 8. Three particles having the same mass and the same horizontal velocity enter a region of constant magnetic field. One particle has a charge q, the other has a charge -2q, and the third particle is neutral. The paths of the particles are shown in Figure 20.520. In which direction does the magnetic field point? Figure 20.52 B Multiple-Choice Problem 8 3. A. Out of the paper B. Into the paper C. Upward D. Downward