Question

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

• A. mass
• B. speed
• C. velocity
• D. momentum

Answer 1

Answer: (C), (D)

momentum

Explanation:

1. The proton's velocity and momentum would be affected by the force acting on it.
2. If the velocity of a charged particle is completely parallel to the magnetic field, the magnetic field exerts no force on the particle, and thus the velocity remains constant.
3. The work done is zero when the force acting is perpendicular to the direction of the moving charge.
4. It means that kinetic energy remains constant.
5. The force can change the proton's direction (velocity), but not its speed (magnitude). As a result, momentum and velocity change.

Hence,Options(C) and (D) are correct.