Electric Field Location problem?

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SUMMARY

The discussion centers on the location of the electric field being zero between a positive and a negative point charge, where the negative charge has a greater magnitude. The correct answer to the problem is that the electric field is zero to the left of the positive charge, not between the charges. A small positive test charge placed between the two will always move towards the negative charge due to the stronger attraction, confirming that the electric field cannot be zero in that region.

PREREQUISITES
  • Understanding of electric fields and point charges
  • Knowledge of Coulomb's Law
  • Familiarity with the concept of electric field lines
  • Basic principles of electrostatics
NEXT STEPS
  • Study the concept of electric field strength and direction
  • Learn about the superposition principle in electrostatics
  • Explore the behavior of test charges in electric fields
  • Review graphical representations of electric fields and equipotential lines
USEFUL FOR

Students studying physics, educators teaching electrostatics, and anyone interested in understanding electric fields and forces between charges.

Blue Crayon
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Hey guys I'm reviewing my notes and I noticed their was a multiple choice problem in my notes that looking back now I just don't understand.

The problem is:
The drawing shows a +ve and a -ve point charge. The -ve charge has the greater magnitude. Where on the line that passes through the charges is the one spot where the total electric field is 0.
c18_q_13.gif



Possible Answers:
A. To the right of the negative charge
B. To the left of the positive charge
C. Between the charges, to the left of the midpoint
D. Between the charges, to the right of the midpoint
----

Looking at this I eliminate A and D right away and honestly my gut feeling then becomes to use C as the way I think of it is the mid point could have to move closer to the +ve charge to balance it out and make it 0. Maybe I am thinking of this all in the wrong sense. Anyways the answer is definitely B as that is what I have circled from my class notes. If someone could explain to me in layman's terms what I am missing I'd really appreciate it!


Thanks!

- BlueCrayon
 
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There is a spot between the charges where the potential is zero, but there is no spot where the E-field is zero. Imagine putting a small positive test charge along the line between the charges. No matter where I put it, it will move to the right, since the + charge repels it and the - charge attracts it. The only place the forces balance (meaning the _field is zero) is to the left of the + charge, where the repulsion of the + charge is directed to the left, and the attraction of the - charge is directed to the right.
 
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I have a common plasma globe with blue streamers and orange pads at both ends. The orange light is emitted by neon and the blue light is presumably emitted by argon and xenon. Why are the streamers blue while the pads at both ends are orange? A plasma globe's electric field is strong near the central electrode, decreasing with distance, so I would not expect the orange color at both ends.

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