(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The electric field intensity between the plates of the Banebridge velocity selector (I am not a native English speaker …) is 120 [Volt/cm] and the magnetic field magnitude of both fields is 0.6 [Weber/m^{2}].

A singly charged Neon ion beam makes a radius of 7.28 [cm]. What is it's mass number.

The result must be 21, 10 times smaller than mine.

2. Relevant equations

Velocity of beam: V=[itex]\frac{E}{B}[/itex]

radius of the beam: [tex]R[m]=\frac{mV}{qB}[/tex]

mass number=mass/proton mass: [tex]N=\frac{m}{m_{p}}[/tex]

3. The attempt at a solution

120[Volt/cm]=12,000[Volt/m]

[tex]V=\frac{E}{B}=\frac{12,000}{0.6}=20,000[m/sec][/tex]

[tex]R=0.728=\frac{mV}{qB}=\frac{m*20,000}{1.602\ \times\ 10^{-19}*0.6}\Rightarrow m=3.5\ \times\ 10^{-25}[/tex]

[tex]N=\frac{m}{m_{p}}=\frac{3.5\ \times\ 10^{-25}}{1.672\ \times\ 10^{-27}}=209[/tex]

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# Homework Help: Magnetic field: the Banebridge velocity selector

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