An Electric Field Perpendicular to a Magnetic Field Is Used

question 68

Multiple Choice

An electric field perpendicular to a magnetic field is used as a velocity selector for Li⁺ ions, selecting the velocity v₁. Next, Li⁺⁺ ions are sent through the same velocity selector, selecting velocity v₂. If neither the electric nor magnetic fields have changed between the two processes, how do v₁ and v₂ compare?

• A) v₂ = v₁
• B) v₂ = 2 v₁
• C) v₂ = v₁/2
• D) v₂ = 4 v₁
• E) v₂ = v₁/4

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