Testing for Charges in X-Y Plane Given Field Lines

AI Thread Summary
The discussion revolves around determining the presence of charges in an X-Y plane based on given electric field lines defined by E=αi(vector)y. The participant acknowledges the challenge of applying the concept of "test for charges" and seeks clarification on expressing charge in equation form. A hint suggests drawing field lines from a charge, emphasizing that field lines originate and terminate at charges. The divergence of the electric field is highlighted as a key factor in applying Gauss' Law to find charge density. The conversation underscores the importance of understanding electric field behavior in relation to charge distribution.
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Homework Statement


The Electric field lines in an X-Y plane are given in the attached image. The field is defined as E=αi(vector)y at x=0 and x=some distance along the positive X axis. α is a positive constant.

Test for charges in the X-Y plane


Homework Equations


N/A


The Attempt at a Solution


The diagram is attached below showing the field lines in the X-Y plane. I understand that the electric field is dependent upon the y-axis only, but am having a tough time figuring out the "test for charges" Perhaps there is a way to describe the charge in equation form?

I already solved the "more difficult" 2nd part of the question - go figure :smile:

A hint I was given was to "draw field lines from a charge". I feel like this is ridiculously simple and I'm missing something silly.

Thanks as always!
 

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The field lines originate at charges and end at charges. The differential form of Gauss' Law says that the divergence of the electric field vector is equal to the charge density/ε0. Determine the divergence of the given electric field.

If you haven't learned divergence yet, you can apply the integral forms of Gauss' Law. Considering any closed surface, what is the net flux?

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