Where an electric field is equal due to two charges?

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SUMMARY

The discussion focuses on determining where the electric field is equal due to two charges. It establishes that the net electric field must be zero, requiring the two fields to be equal in magnitude and opposite in direction. The positive charge generates an electric field directed away from it, while the negative charge creates a field directed towards it. The analysis concludes that the regions of interest are I and IV, where the fields can potentially cancel each other out due to their respective strengths, which vary with distance from the charges.

PREREQUISITES
  • Understanding of electric fields and their directionality
  • Knowledge of Coulomb's Law and its application to point charges
  • Familiarity with the concept of field strength and its dependence on distance
  • Basic grasp of vector addition in physics
NEXT STEPS
  • Study the principles of Coulomb's Law in detail
  • Learn about electric field lines and their representation
  • Explore the concept of superposition of electric fields
  • Investigate the mathematical formulation of electric field strength
USEFUL FOR

Students of physics, educators teaching electromagnetism, and anyone interested in understanding the behavior of electric fields in the presence of multiple charges.

mirandab17
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Hey there!

I don't understand how this really works. With each region, how is it that the charges carry over...? The answer is the fourth region. I'm just totally lost, please explain to me. :)
 
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mirandab17 said:
Picture14.png


Hey there!

I don't understand how this really works. With each region, how is it that the charges carry over...? The answer is the fourth region. I'm just totally lost, please explain to me. :)

The net electric field is to be zero, so the two fields must separately be in opposite directions - and of equal magnitude.

The electric field due to the positive charge is away from the charge, so left in region I, and right in regions II, III and IV.

The electric field due to a negative charge is towards the charge, so right in regions I, II & III, and left in region IV.

Only in regions I and IV are the two field in opposite direction, so we know it is one of them.

The strength of the field, E, drops off with distance - the further you are from the charge, the smaller the field, E.
AND
The larger the charge, the stronger the field, E, for any specific distance.

In region I, you are closer [stronger E] to the larger [stronger E] charge, so the effects of the + charge will always dominate.

In region IV, you are closer [stronger E] to the smaller [weaker E] charge, so there may be a point where the two fields can effectively cancel.
 

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