A2L Item 200

Goal: Distinguishing components of the Lorentz force

Source: 283 – effects of magnetic force

A charged particle moves into a region containing both an electric and
magnetic field. Which of the statements below are true?

  1. The particle cannot accelerate in the
    direction of B.
  2. The path of the particle must be a circle.
  3. Any change in the particle’s kinetic energy is caused by the E
  1. Only A
  2. Only B
  3. Only C
  4. Both A&B
  5. Both A&C
  6. Both B&C
  7. All are true.
  8. None are true.



(3) The only cases that most students see is the one having E and B
perpendicular. As a result they discount the case of E and B parallel
and think statement A is also true.