As a proton passes the origin, its velocity is $3.0\times {10}^5\mathrm{m}/\mathrm{s}$in the positive x direction. What is the magnitude of the magnetic field at the point ($12.0\mathrm{cm}$, $5.0\mathrm{cm}$, $0.0\mathrm{cm}$)?

• A. $1.2\times {10}^{-20}\mathrm{T}$
• B. $5.2\times {10}^{-20}\mathrm{T}$
• C. $9.2\times {10}^{-20}\mathrm{T}$
• D. $1.8\times {10}^{-19}\mathrm{T}$
• E. $2.4\times {10}^{-19}\mathrm{T}$
• F. 1.1 x 10^-19 T