Question 23M.3.HL.TZ1.3
| Date | May 2023 | Marks available | [Maximum mark: 3] | Reference code | 23M.3.HL.TZ1.3 |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Discuss, Outline | Question number | 3 | Adapted from | N/A |
A proton is moving in a region of magnetic field of strength B. The speed of the proton relative to the magnetic field is v.
In the reference frame in which the magnetic field is at rest, the proton experiences an initial magnetic force evB upwards.
Outline why there can be no magnetic force on the proton in the proton’s rest frame.
[1]
«in the proton rest frame » the speed of the proton is zero so force is zero ✓
Proton in a magnetic field. Students well outlined that magnetic force requires particles in motion.
Discuss the nature of the force in the proton’s rest frame.
[2]
the proton sees an electric field / experiences electric force ✓
upward force ✓
In b), only better students identified the direction of the force and the electric nature of the force.
