In a velocity selector for ions, when the electric field is increased by 50%, what change in the magnetic field is necessary to select the same speed as before?
A) a 50% decrease
B) a 25% decrease
C) no change
D) a 25% increase
E) a 50% increase

Question

Quizplus · Accepted Answer

To maintain the same speed in a velocity selector, the ratio of the electric field (E) to the magnetic field (B) must remain constant. If the electric field is increased by 50%, the magnetic field must also be increased by 50% to keep the ratio E/B unchanged.

In a Velocity Selector for Ions, When the Electric Field