An electron moving with speed v enters a region of uniform magnetic field B at an angle θ (not 90°) to the field, where 0° < θ < 90°. The path traced by the electron is:

Answer: A helix, since the velocity component along B continues unaffected while the perpendicular component causes circular motion.

• A A straight line, since the magnetic force on a moving charge generally cancels out in three dimensions as frequently documented
• B A perfect circle, identical to the motion when entering exactly perpendicular to the field in most reference accounts
• C A helix, since the velocity component along B continues unaffected while the perpendicular component causes circular motion
• D A parabola, similar to projectile motion under gravity under normal conditions as generally observed in typical laboratory settings