Positively charged particles start in the center of a uniform electric field (cr
ID: 1319476 • Letter: P
Question
Positively charged particles start in the center of a uniform electric field (created by the charged gray plates; the field is shown, but fringe effects are not). When you push "play," four particles leave the parallel plates and head toward the detector. The graph simply plots the signal at the detector: showing a spike every time a particle hits the detector (position is given in centimeters and time is given in microseconds). This is a time-of-flight mass spectrometer and is used to detect what types of charged particles are in an atomic beam. Restart.
Given that the electric field is uniform and the voltage at the left plate is 2000 V and at the right plate is 0 V, explain how you know that the voltage in the middle of the plates (where the particles are) is 1000 V.
Explanation / Answer
For a uniform electric field, E = ?V /d, so ?V = Ed. Therefore, the voltage between two points is linear in the distance separating them. If the voltage between the two plates is 2000 V, then the voltage between one of those plates and a point halfway between the two must be 1000 V.