Deflection distance for an electron beam in an electric field

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Homework Help Overview

The discussion revolves around the deflection distance of an electron beam in an electric field, a topic within the realm of electromagnetism. Participants are examining the calculations related to the beam's trajectory and the influence of the electric field on its path.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants are sharing their calculations and questioning the correctness of their results. There is confusion regarding the direction of the electric field and its effect on the electron's deflection. Some participants suggest that there may be an error in the problem statement itself, particularly concerning the values provided.

Discussion Status

The discussion is ongoing, with participants providing feedback on each other's work. Some have expressed agreement with specific calculations while questioning the assumptions made regarding the electric field's direction. There is a suggestion that the problem may contain errors, but no consensus has been reached on the correct interpretation or resolution.

Contextual Notes

Participants note potential discrepancies in the problem statement, including concerns about the accuracy of the given values and the possibility of a decimal point error. There is also mention of the frequency of such issues in updated problem sets.

Bolter
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Homework Statement
See question below
Relevant Equations
F = qE
Have tried doing this question but I'm a bit confused on where I'm going wrong

Screenshot 2020-03-07 at 22.32.02.png

This is what I have done but get a value that doesn't match to any of the options given above?

IMG_4055.JPG


Any help would be really appreciated, Thanks!
 
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I agree with your answer of 17.6 cm. Your work looks very good. But in your diagram, if the electric field is downward, would the electron be deflected downward?
 
TSny said:
I agree with your answer of 17.6 cm. Your work looks very good. But in your diagram, if the electric field is downward, would the electron be deflected downward?

Sorry my field line directions should be reversed (going from positive to negative)

So the question must have a mistake then I guess. I believe the first option would’ve been the right answer but maybe the person who wrote this misplaced the decimal point position and instead got 1.76cm and not 17.6cm :oldconfused:
 
Bolter said:
Sorry my field line directions should be reversed (going from positive to negative)

So the question must have a mistake then I guess. I believe the first option would’ve been the right answer but maybe the person who wrote this misplaced the decimal point position and instead got 1.76cm and not 17.6cm :oldconfused:
Yup. Given the question-given values the beam will impact the positive plate about halfway through the parallel plate channel. So original problem statement FAIL. This happens frustratingly frequently, especially when older problem sets are "updated" to change the working values to "refresh" the problem for new editions of texts or exams.
 
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