Magnetism and Moving Charges Practice Test

A particle with charge $q=-2.0\times10^{-6}\ \text{C}$ moves at $1.5\times10^{3}\ \text{m/s}$ due north through a uniform magnetic field $\vec{B}=0.20\ \text{T}$ directed due north. No electric fields are present. Which statement best describes the magnetic force on the particle?

A proton ($q=+1.60\times10^{-19}\ \text{C}$) enters a region of uniform magnetic field $\vec{B}=0.50\ \text{T}$ directed east. The proton’s velocity is $3.0\times10^{6}\ \text{m/s}$ directed north. No electric fields are present. Which statement best describes the magnetic force on the proton?