A proton, moving in a uniform magnetic field, moves in a circle perpendicular to the field lines and takes time T for each circle. If the proton's speed tripled, what would now be its time to go around
Each circle?
A) $T / 9$
B) $3 T$
C) $9 T$
D) $T$
E) $T / 3$

Question

A proton, moving in a uniform magnetic field, moves in a circle perpendicular to the field lines and takes time T for each circle. If the proton's speed tripled, what would now be its time to go around
Each circle? 
A) $T / 9$
B) $3 T$
C) $9 T$
D) $T$
E) $T / 3$

Quizplus · Accepted Answer

The time period for a charge moving in a uniform magnetic field is independent of its speed. It only depends on the charge, mass of the particle, and the magnetic field strength.

A Proton, Moving in a Uniform Magnetic Field, Moves in a Circle