question_answer 26)

Which of the following property of a proton can change while it moves freely in a magnetic field? (There may be more than one correct answer.) (a) mass                               (b) speed                            (c) velocity                          (d) momentum

Answer:

The correct answers are (c) and (d). Each moving charged particle in a magnetic field experiences a force. The direction of force experienced by a positive charge (i.e., a proton) is given by Fleming's left hand rule. The force acting on the proton would change both velocity and momentum.