A particle carrying a charge of +e travels in a circular path of radius R in a uniform magnetic field. If instead the particle carried a charge of +2e, the radius of the circular path would have been
A) $R / 2$.
B) $R / 4$.
C) $2 R$.
D) $4 R$.
E) $8 R$.

Question

A particle carrying a charge of +e travels in a circular path of radius R in a uniform magnetic field. If instead the particle carried a charge of +2e, the radius of the circular path would have been 
A) $R / 2$.
B) $R / 4$.
C) $2 R$.
D) $4 R$.
E) $8 R$.

Quizplus · Accepted Answer

The radius of the circular path of a charged particle in a magnetic field is inversely proportional to the charge of the particle. Doubling the charge from +e to +2e will halve the radius, making it $R / 2$.

A Particle Carrying a Charge of +E Travels in a Circular